Bowling ball: Difference between revisions
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{{Short description|Ball used to hit pins in the sport of bowling}} |
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{{other uses}} |
{{other uses}} |
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[[File:20190103 Bowling ball sizes.png |thumb|right |upright=1.5 | Comparative sizes of bowling balls, portrayed on boards of a bowling lane |
[[File:20190103 Bowling ball sizes.png |thumb|right |upright=1.5 | Comparative sizes of bowling balls, portrayed on boards of a bowling lane]] |
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A '''bowling ball''' is a hard spherical [[Ball (sports)|ball]] used to knock down [[bowling pin]]s in the sport of [[bowling]]. |
A '''bowling ball''' is a hard spherical [[Ball (sports)|ball]] used to knock down [[bowling pin]]s in the sport of [[bowling]]. |
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===Specifications=== |
===Specifications=== |
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{{multiple image |
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| image1 = 1892 Ten Pins and Bowling Balls - advertisement - Spalding's Athletic Library.jpg |
| image1 = 1892 Ten Pins and Bowling Balls - advertisement - Spalding's Athletic Library.jpg |
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| caption1= |
| caption1 = This 1892 ad shows [[Lignum vitae]] (hardwood) balls of various sizes in addition to larger, "regulation" balls.<ref name=SpaldingAthleticLibrary_189212>{{cite magazine |title=Bowling |url=http://www.hucosystems.com/articles/First%20Job.htg/bowling2.pdf |magazine=Spalding's Athletic Library |volume=1 |issue= 3 |publisher=American Sports Publishing Company |date=December 1892 |archive-url=https://web.archive.org/web/20200327135438/http://www.hucosystems.com/articles/First%20Job.htg/bowling2.pdf |archive-date=March 27, 2020 |location=New York |url-status=dead }}</ref> |
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| image2 = 18941218 Bowling ball - U.S. Patent 531,103.png |
| image2 = 18941218 Bowling ball - U.S. Patent 531,103.png |
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| caption2= This 1894 patent shows how bowling balls once had a thumb hole and only a single finger hole. Bowling balls of the era were made of [[lignum vitae]] (hardwood).<ref name=BBevolution2012/> |
| caption2 = This 1894 patent shows how bowling balls once had a thumb hole and only a single finger hole. Bowling balls of the era were made of [[lignum vitae]] (hardwood).<ref name=BBevolution2012/> |
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| image3 = 20190118A Plastic house bowling ball conventional grip.jpg |
| image3 = 20190118A Plastic house bowling ball conventional grip.jpg |
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| caption3= A polyester ("plastic") house ball, having large |
| caption3 = A polyester ("plastic") house ball, having large, non-custom holes in a ''conventional grip'' (fingers insert to the second knuckle; thumb hole relatively close to the finger holes) |
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| title = Balls with custom finger inserts in a ''fingertip grip''<br>(fingers insert only to first knuckle) |
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| image5 = 20190222 Urethane bowling ball fingertip grip.jpg |
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The [[United States Bowling Congress|USBC]] and [[World Bowling]] promulgate bowling ball specifications. USBC specifications include physical requirements for weight (≤{{convert|16|lb|kg}}), diameter ({{convert|8.500|in|cm }}—{{convert|8.595|in|cm}}), surface hardness, surface roughness, hole drilling limitations (example: a single balance hole ''including'' the thumb hole for "two-handed" bowlers<ref name=USBCgripping20140507>{{cite web |last1=Wiseman |first1=Lucas |author2=United States Bowling Congress (USBC) |title=USBC Modifies Rule on Bowling Ball Gripping holes |url=https://www.bowl.com/News/NewsDetails.aspx?id=23622321723 |website=bowl.com (United States Bowling Congress, USBC) |archive-url=https://web.archive.org/web/20170707095658/https://www.bowl.com/News/NewsDetails.aspx?id=23622321723 |archive-date=July 7, 2017 |date=May 7, 2014 |url-status=live }}</ref>), balance, plug limitations, and exterior markings (structural and commercial), as well as requirements for dynamic performance characteristics such as radius of gyration (RG; 2.46—2.80), RG differential (≤0.06), and coefficient of friction (≤0.32).<ref name=USBCspecs2012>{{cite web |title=USBC Equipment Specifications and Certifications Manual |url=https://bowl.com/uploadedFiles/Equipment_Specs/Information/2012FebESManualWEBINTERACTIVE.pdf |website=bowl.com (United States Bowling Congress, USBC) |archive-url=https://web.archive.org/web/20181229031504/https://bowl.com/uploadedFiles/Equipment_Specs/Information/2012FebESManualWEBINTERACTIVE.pdf |archive-date=December 29, 2018 |date=February 2012 |url-status=live }}</ref> The USBC banned [[Glossary of bowling#Balance hole|weight holes (balance holes)]] in competition, effective August 1, 2020, to prevent their changing ball dynamics.<ref name=USBC_20180424>{{cite web |last1=Bigham |first1=Terry |title=Bowling Technology Study Conclusion / Research Summary and Specification Updates |url=https://www.bowl.com/News/NewsDetails.aspx?id=23622331019 |website=Bowl.com |publisher=United States Bowling Congress (USBC) |archive-url=https://web.archive.org/web/20190526210733/https://www.bowl.com/News/NewsDetails.aspx?id=23622331019 |archive-date=May 26, 2019 |date=April 24, 2018 |url-status=live }}</ref> The USBC permits three ounces (85 grams) of static side weight and three ounces (85 grams) of top weight. These figures are up from one ounce (28 grams) following the August 1, 2020 rule change.<ref>{{cite web |url=https://www.bowlersmart.com/2020/03/19/2020-usbc-rule-changes-on-bowling-ball-weight-holes-by-mdm-coaching/ |title=2020 USBC Rule Changes On Bowling Ball Weight Holes By MDM Bowling Coaching |last=Barnes |first=Clifton |website=bowlersmart.com |date=March 19, 2020 |archive-url=https://web.archive.org/web/20201113213045/https://www.bowlersmart.com/2020/03/19/2020-usbc-rule-changes-on-bowling-ball-weight-holes-by-mdm-coaching/ |archive-date=November 13, 2020 |url-status=live }}</ref> |
The [[United States Bowling Congress|USBC]] and [[World Bowling]] promulgate bowling ball specifications. USBC specifications include physical requirements for weight (≤{{convert|16|lb|kg}}), diameter ({{convert|8.500|in|cm }}—{{convert|8.595|in|cm}}), surface hardness, surface roughness, hole drilling limitations (example: a single balance hole ''including'' the thumb hole for "two-handed" bowlers<ref name=USBCgripping20140507>{{cite web |last1=Wiseman |first1=Lucas |author2=United States Bowling Congress (USBC) |title=USBC Modifies Rule on Bowling Ball Gripping holes |url=https://www.bowl.com/News/NewsDetails.aspx?id=23622321723 |website=bowl.com (United States Bowling Congress, USBC) |archive-url=https://web.archive.org/web/20170707095658/https://www.bowl.com/News/NewsDetails.aspx?id=23622321723 |archive-date=July 7, 2017 |date=May 7, 2014 |url-status=live }}</ref>), balance, plug limitations, and exterior markings (structural and commercial), as well as requirements for dynamic performance characteristics such as radius of gyration (RG; 2.46—2.80), RG differential (≤0.06), and coefficient of friction (≤0.32).<ref name=USBCspecs2012>{{cite web |title=USBC Equipment Specifications and Certifications Manual |url=https://bowl.com/uploadedFiles/Equipment_Specs/Information/2012FebESManualWEBINTERACTIVE.pdf |website=bowl.com (United States Bowling Congress, USBC) |archive-url=https://web.archive.org/web/20181229031504/https://bowl.com/uploadedFiles/Equipment_Specs/Information/2012FebESManualWEBINTERACTIVE.pdf |archive-date=December 29, 2018 |date=February 2012 |url-status=live }}</ref> The USBC banned [[Glossary of bowling#Balance hole|weight holes (balance holes)]] in competition, effective August 1, 2020, to prevent their changing ball dynamics.<ref name=USBC_20180424>{{cite web |last1=Bigham |first1=Terry |title=Bowling Technology Study Conclusion / Research Summary and Specification Updates |url=https://www.bowl.com/News/NewsDetails.aspx?id=23622331019 |website=Bowl.com |publisher=United States Bowling Congress (USBC) |archive-url=https://web.archive.org/web/20190526210733/https://www.bowl.com/News/NewsDetails.aspx?id=23622331019 |archive-date=May 26, 2019 |date=April 24, 2018 |url-status=live }}</ref> The USBC permits three ounces (85 grams) of static side weight and three ounces (85 grams) of top weight. These figures are up from one ounce (28 grams) following the August 1, 2020 rule change.<ref>{{cite web |url=https://www.bowlersmart.com/2020/03/19/2020-usbc-rule-changes-on-bowling-ball-weight-holes-by-mdm-coaching/ |title=2020 USBC Rule Changes On Bowling Ball Weight Holes By MDM Bowling Coaching |last=Barnes |first=Clifton |website=bowlersmart.com |date=March 19, 2020 |archive-url=https://web.archive.org/web/20201113213045/https://www.bowlersmart.com/2020/03/19/2020-usbc-rule-changes-on-bowling-ball-weight-holes-by-mdm-coaching/ |archive-date=November 13, 2020 |url-status=live }}</ref> |
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===Coverstock technology=== |
===Coverstock technology=== |
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{{see|#Effect of coverstock, core and layout on ball motion}} |
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[[File:20190310 Bowling ball coverstock timeline.png | thumb|right |upright=1.5 | A rough timeline of ten-pin bowling ball coverstock technology |
[[File:20190310 Bowling ball coverstock timeline.png | thumb|right |upright=1.5 | A rough timeline of ten-pin bowling ball coverstock technology<ref name=BBevolution2012/><ref name=Siefers20070423/>]] |
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Bowling balls were made of [[lignum vitae]] (hardwood) until the 1905 introduction of rubber balls.<ref name=BBevolution2012>{{cite web |last1=Carrubba |first1=Rich |title=Bowling Ball Evolution |url=https://www.bowlingball.com/BowlVersity/bowling-ball-evolution | |
Bowling balls were made of [[lignum vitae]] (hardwood) until the 1905 introduction of rubber balls.<ref name=BBevolution2012>{{cite web |last1=Carrubba |first1=Rich |title=Bowling Ball Evolution |url=https://www.bowlingball.com/BowlVersity/bowling-ball-evolution |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20180917215354/https://www.bowlingball.com/BowlVersity/bowling-ball-evolution |archive-date=September 17, 2018 |date=June 2012 |url-status=live }}</ref> Polyester ("plastic") balls were introduced in 1959 and, despite developing less hook-generating lane friction than rubber balls, by the 1970s plastic dominated over rubber balls.<ref name=BBevolution2012/> Briefly, "soaker" ball technology—involving softening coverstocks to achieve greater hook—were used, until rules for minimum hardness were implemented.<ref name=BBcom_20110512>{{cite web |last1=Martin |first1=Jimmy |title=The Evolution of Bowling Balls |url=https://www.bowlingball.com/bowlversity/the-evolution-of-bowling-balls |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20220926092319/https://www.bowlingball.com/bowlversity/the-evolution-of-bowling-balls |archive-date=September 26, 2022 |date=May 12, 2011 |url-status=live}}</ref> The early-1980s development of polyurethane ("urethane") balls developed more friction with the newly developed polyurethane lane finishes of the day, sparking the evolution of coverstock technology to pursue ever-stronger hooks with correspondingly higher [[Glossary of bowling#Angle of entry|entry angles]].<ref name=BBevolution2012/><ref name=BTM_Balls_20170331>{{cite magazine |title=Bowling Balls: An In-Depth Overview |url=https://www.bowlingthismonth.com/bowling-balls/ |magazine=Bowling This Month |archive-url=https://web.archive.org/web/20190412221716/https://www.bowlingthismonth.com/bowling-balls/ |archive-date=April 12, 2019 |date=March 31, 2017 |url-status=live }}</ref> |
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The early 1990s brought development of reactive resin ("reactive") balls by introducing additives in urethane surface materials to create microscopic oil-absorbing pores that increase the "tackiness" that enhances traction.<ref name=BBevolution2012/><ref name=Siefers20070423/><ref name=BTM_Balls_20170331/> In the "particle-enhanced" balls developed in the late 1990s, microscopic particles embedded in reactive coverstocks reach through oil lane coatings to provide even greater traction.<ref name=BBevolution2012/><ref name=Siefers20070423/> Ball manufacturers developed closely guarded proprietary blends including ground-up material such as glass, ceramic or rubber, to enhance friction.<ref name=NYTimes20000421>{{cite news |last1=Barry |first1=Dan |title=Perfection Made Easy; Bowling a 300 Game Just Isn't the Feat It Used to Be |url=https://www.nytimes.com/2000/04/21/nyregion/perfection-made-easy-bowling-a-300-game-just-isn-t-the-feat-it-used-to-be.html |work=The New York Times |date=April 21, 2000 |archive-url=https://web.archive.org/web/20160607094256/http://www.nytimes.com/2000/04/21/nyregion/perfection-made-easy-bowling-a-300-game-just-isn-t-the-feat-it-used-to-be.html?pagewanted=all |archive-date=June 7, 2016 |url-status=live }}</ref> |
The early 1990s brought development of reactive resin ("reactive") balls by introducing additives in urethane surface materials to create microscopic oil-absorbing pores that increase the "tackiness" that enhances traction.<ref name=BBevolution2012/><ref name=Siefers20070423/><ref name=BTM_Balls_20170331/> In the "particle-enhanced" balls developed in the late 1990s, microscopic particles embedded in reactive coverstocks reach through oil lane coatings to provide even greater traction.<ref name=BBevolution2012/><ref name=Siefers20070423/> Ball manufacturers developed closely guarded proprietary blends including ground-up material such as glass, ceramic or rubber, to enhance friction.<ref name=NYTimes20000421>{{cite news |last1=Barry |first1=Dan |title=Perfection Made Easy; Bowling a 300 Game Just Isn't the Feat It Used to Be |url=https://www.nytimes.com/2000/04/21/nyregion/perfection-made-easy-bowling-a-300-game-just-isn-t-the-feat-it-used-to-be.html |work=The New York Times |date=April 21, 2000 |archive-url=https://web.archive.org/web/20160607094256/http://www.nytimes.com/2000/04/21/nyregion/perfection-made-easy-bowling-a-300-game-just-isn-t-the-feat-it-used-to-be.html?pagewanted=all |archive-date=June 7, 2016 |url-status=live }}</ref> |
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Within the reactive category are ''solid'' reactive coverstocks (having the greatest amount of microscopic pores), ''pearl'' reactive coverstocks (including [[mica]] additives that enhance reaction on dry lane surfaces), ''hybrid'' reactive coverstocks (combining the mid-lane reaction of solid coverstocks and the back-end reaction of pearl coverstocks), and ''particle'' coverstocks (including microscopic silica particles, favored for use on heavy oil volumes).<ref name=BBevolution2012/><ref name=BTM_Balls_20170331/><ref name=BBCom_20130101>{{cite web |last1=Carrubba |first1=Rich |title=Reactive Bowling Balls |url=https://www.bowlingball.com/bowlversity/reactive-bowling-balls | |
Within the reactive category are ''solid'' reactive coverstocks (having the greatest amount of microscopic pores), ''pearl'' reactive coverstocks (including [[mica]] additives that enhance reaction on dry lane surfaces), ''hybrid'' reactive coverstocks (combining the mid-lane reaction of solid coverstocks and the back-end reaction of pearl coverstocks), and ''particle'' coverstocks (including microscopic silica particles, favored for use on heavy oil volumes).<ref name=BBevolution2012/><ref name=BTM_Balls_20170331/><ref name=BBCom_20130101>{{cite web |last1=Carrubba |first1=Rich |title=Reactive Bowling Balls |url=https://www.bowlingball.com/bowlversity/reactive-bowling-balls |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20200806065244/https://www.bowlingball.com/bowlversity/reactive-bowling-balls |archive-date=August 6, 2020 |date=January 1, 2013 |url-status=live }}</ref> |
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Hook potential has increased so much that dry lane conditions or certain spare shots sometimes cause bowlers to use plastic or urethane balls, to purposely avoid the larger hook provided by reactive technology.<ref name=BBevolution2012/><ref name=Siefers20070423>{{cite web |last1=Siefers |first1=Nick (USBC research engineer) |title=Understanding the relationship between core and cover stock |url=https://www.bowlingdigital.com/bowl/node/2324 |website=BowlingDigital.com (Courtesy of USBC Equipment Specification and Certification) |archive-url=https://web.archive.org/web/20180920011257/https://www.bowlingdigital.com/bowl/node/2324 |archive-date=September 20, 2018 |date=April 23, 2007 |url-status=live }}</ref> |
Hook potential has increased so much that dry lane conditions or certain spare shots sometimes cause bowlers to use plastic or urethane balls, to purposely avoid the larger hook provided by reactive technology.<ref name=BBevolution2012/><ref name=Siefers20070423>{{cite web |last1=Siefers |first1=Nick (USBC research engineer) |title=Understanding the relationship between core and cover stock |url=https://www.bowlingdigital.com/bowl/node/2324 |website=BowlingDigital.com (Courtesy of USBC Equipment Specification and Certification) |archive-url=https://web.archive.org/web/20180920011257/https://www.bowlingdigital.com/bowl/node/2324 |archive-date=September 20, 2018 |date=April 23, 2007 |url-status=live }}</ref> |
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===Layout and grip=== |
===Layout and grip=== |
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{{xref|See also: {{slink||Effect of coverstock, core and layout on ball motion}}}} |
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A ball's ''drilling [[Glossary of bowling#Layout|layout]]'' refers to how and where holes are drilled, in relation to the ball's locator pin and mass bias (MB) marker.<ref name=BTM_Balls_20170331/><ref name=BBdrill201501>{{cite web |title=How Should My Bowling Ball Be Drilled? |url=https://www.bowlingball.com/wordpress/how-should-my-bowling-ball-be-drilled | |
A ball's ''drilling [[Glossary of bowling#Layout|layout]]'' refers to how and where holes are drilled, in relation to the ball's locator pin and mass bias (MB) marker.<ref name=BTM_Balls_20170331/><ref name=BBdrill201501>{{cite web |title=How Should My Bowling Ball Be Drilled? |url=https://www.bowlingball.com/wordpress/how-should-my-bowling-ball-be-drilled |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20150711104913/https://www.bowlingball.com/wordpress/how-should-my-bowling-ball-be-drilled |archive-date=July 11, 2015 |date=January 2015 |url-status=live }}</ref> Layout is determined with reference to each bowler's ''[[Glossary of bowling#PAP|positive axis point]]'' (PAP{{px2}}{{mdash}}{{hsp}}the pocket end of the ball's initial axis of rotation).<ref name=BBpap201211>{{cite web |last1=Carrubba |first1=Rich |title=Your Bowling Ball Positive Axis Point |url=https://www.bowlingball.com/BowlVersity/your-bowling-ball-positive-axis-point |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20170709173226/https://www.bowlingball.com/BowlVersity/your-bowling-ball-positive-axis-point |archive-date=July 9, 2017 |date=November 2012 |url-status=live }}</ref> "Pin down" layouts place the pin between the finger holes and the thumb hole, while "pin up" layouts place the pin further from the thumb hole than the finger holes (see photos).<ref name=BBdrill201501/><ref name=CTDpinUpDown20170411>{{cite web |last1=Hickland |first1=Ronald |title=What is the difference between Pin up and Pin down Drilling on a Bowling Ball? |url=https://ctdbowling.com/blogs/news/what-is-the-difference-between-pin-up-and-pin-down-drilling-on-a-bowling-ball |website=CTDbowling.com News section |date=April 11, 2017}} (Web page archiving attempts failed.)</ref> Bowling ball motion is influenced by how far the pin and the mass bias (MB) are from the PAP, the distances determining ''[[Glossary of bowling#Track flare|track flare]].''<ref name=BBpap201211/> Track flare—the sequence of oil rings showing migration of the ball's axis on successive revolutions through the oil pattern—is popularly thought to influence [[Glossary of bowling#Angle of entry|entry angle]],<ref name=BBpap201211/> but Freeman & Hatfield (2018) discount its contribution to ball motion.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?") }} |
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[[File:Bowlingball3.gif |thumb|250px |'''Side view of ball motion:''' The ball initially skids after first contact with the oily part of the lane, but enters a roll phase as full traction is eventually obtained in the dry portion of the lane. Side rotation and hook are not illustrated.]] |
[[File:Bowlingball3.gif |thumb|250px |'''Side view of ball motion:''' The ball initially skids after first contact with the oily part of the lane, but enters a roll phase as full traction is eventually obtained in the dry portion of the lane. Side rotation and hook are not illustrated.]] |
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Holes may be drilled for a ''conventional'' grip (fingers inserted to the second knuckle as with "house balls"), a ''fingertip'' grip (fingers inserted only to the first knuckle, enabling greater rev-generating torque), or less standard grips such as the ''Sarge Easter'' grip (ring finger inserted to the second knuckle but middle finger inserted only to the first knuckle).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 5 ("You Say You Want a Revolution") }} Many bowlers using the so-called "two-handed delivery" (which is still a ''one''-handed ''release'') do not insert their thumbs, thus allowing their fingers to impart even more torque than the fingertip grip.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 5 ("You Say You Want a Revolution") }} |
Holes may be drilled for a ''conventional'' grip (fingers inserted to the second knuckle as with "house balls"), a ''fingertip'' grip (fingers inserted only to the first knuckle, enabling greater rev-generating torque), or less standard grips such as the ''Sarge Easter'' grip (ring finger inserted to the second knuckle but middle finger inserted only to the first knuckle).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 5 ("You Say You Want a Revolution") }} Many bowlers using the so-called "two-handed delivery" (which is still a ''one''-handed ''release'') do not insert their thumbs, thus allowing their fingers to impart even more torque than the fingertip grip.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 5 ("You Say You Want a Revolution") }} |
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Finger inserts and thumb slugs are custom-fit urethane tubes inserted into the drilled holes, generally for balls with a fingertip grip.<ref name=BBinserts2013/> Finger inserts enhance the torque provided by the fingers after the thumb exits the ball.<ref name=BBinserts2013>{{cite web |title=Finger Inserts For New Bowlers |url=https://www.bowlingball.com/wordpress/finger-inserts-for-new-bowlers | |
Finger inserts and thumb slugs are custom-fit urethane tubes inserted into the drilled holes, generally for balls with a fingertip grip.<ref name=BBinserts2013/> Finger inserts enhance the torque provided by the fingers after the thumb exits the ball.<ref name=BBinserts2013>{{cite web |title=Finger Inserts For New Bowlers |url=https://www.bowlingball.com/wordpress/finger-inserts-for-new-bowlers |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20190116185722/https://www.bowlingball.com/wordpress/finger-inserts-for-new-bowlers |archive-date=January 16, 2019 |date=2013 |url-status=live }}</ref> |
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{{anchor|Ball motion|ball motion}} |
{{anchor|Ball motion|ball motion}} |
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===Ball motion=== |
===Ball motion=== |
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[[File:20200417 Bowling ball motion and release ratio.gif |thumb |upright=1.5 | |
[[File:20200417 Bowling ball motion and release ratio.gif |thumb |upright=1.5 | Progression of various quantities as the ball moves down the lane: |
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<br>{{nbs|3}}•{{nbs|2}}ball's direction and waning speed (direction and size of brown arrows) |
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<br>{{nbs|3}}•{{nbs|2}}increasing rev rate (motion of yellow arrowheads) |
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<br>{{nbs|3}}•{{nbs|2}}evolving axis rotation (direction of yellow arrowheads) |
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<br>{{nbs|3}}•{{nbs|2}}convergence of the ball's forward (translational) speed and rev rate (rotational speed) (bottom chart)]] |
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A complex interaction of a variety of factors influences ball motion and its effect on scoring results.<ref name=BowlingBallCom_20150413>{{cite web |title=What Are The Boiled Down Factors Affecting Bowling Ball Motion? |url=https://www.bowlingball.com/bowlversity/what-are-the-boiled-down-factors-affecting-bowling-ball-motion | |
A complex interaction of a variety of factors influences ball motion and its effect on scoring results.<ref name="BBcom_20111002">{{cite web |last1=Carrubba |first1=Rich |title=Understanding Bowling Ball Motion |url=https://www.bowlingball.com/bowlversity/understanding-bowling-ball-motion |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20230505092332/https://www.bowlingball.com/bowlversity/understanding-bowling-ball-motion |archive-date=May 5, 2023 |date=October 2, 2011 |url-status=live}}</ref><ref name=BowlingBallCom_20150413>{{cite web |title=What Are The Boiled Down Factors Affecting Bowling Ball Motion? |url=https://www.bowlingball.com/bowlversity/what-are-the-boiled-down-factors-affecting-bowling-ball-motion |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20150818212830/https://www.bowlingball.com/bowlversity/what-are-the-boiled-down-factors-affecting-bowling-ball-motion |archive-date=August 18, 2015 |date=April 13, 2015 |url-status=live}}</ref><ref name=BBcom_Motion_20130205/><ref name=BowlingBallComBallMotion_20161229/><ref name=BowlingBallCom_Variables_20160418/> The factors may be categorized as the bowler's delivery, the bowling ball's design, and the condition of the lane. |
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====Stages of ball motion==== |
====Stages of ball motion==== |
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Bowling ball motion<ref name=BBcom_Motion_20130205>{{cite web |last1=Carrubba |first1=Rich |title=The Simple Keys Of Bowling Ball Motion |url=https://www.bowlingball.com/bowlversity/the-simple-keys-of-bowling-ball-motion?bowlversityarticleid=13127 | |
Bowling ball motion<ref name=BBcom_Motion_20130205>{{cite web |last1=Carrubba |first1=Rich |title=The Simple Keys Of Bowling Ball Motion |url=https://www.bowlingball.com/bowlversity/the-simple-keys-of-bowling-ball-motion?bowlversityarticleid=13127 |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20210723194311/https://www.bowlingball.com/bowlversity/the-simple-keys-of-bowling-ball-motion?bowlversityarticleid=13127 |archive-date=July 23, 2021 |date=February 5, 2013 |url-status=live }}</ref> is commonly broken down into sequential skid, hook, and roll phases.{{sfn |Stremmel |Ridenour | Stervenz |2008 |p=3 }}<ref name=BBcom3PhasesMotion20160728>{{cite web |title=Bowling Ball Reaction Keys |url=https://www.bowlingball.com/bowlversity/bowling-ball-reaction-keys |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20161110035756/http://www.bowlingball.com/BowlVersity/bowling-ball-reaction-keys |archive-date=November 10, 2016 |date=July 28, 2016 |url-status=live}}</ref> As the ball travels down the lane in the skid and hook phases, frictional contact with the lane causes the ball's forward (''translational'') speed to continually decrease, but to continually increase its [[Glossary of bowling#Rev rate|rev rate]] (''rotational'' speed).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} Especially as the ball encounters greater friction in the last ≈20 feet (approximate) of the lane, the ball's [[Glossary of bowling#Axis rotation|axis rotation]] (side rotation) causes the ball to [[hook (bowling)|hook]] away from its original direction.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} Concurrently, lane friction continually decreases the angle of axis rotation until it exactly matches the direction of the ball's forward motion, and rev rate (rotational speed) increases until it exactly matches the ball's forward speed: full traction is achieved and the ball enters the roll phase in which forward speed continues to decrease.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} |
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====Effect of delivery characteristics on ball motion==== |
====Effect of delivery characteristics on ball motion==== |
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''[[Glossary of bowling#Release ratio|Release ratio]]'' denotes the ratio of the ball's forward (translational) speed to its rev rate (rotational speed) at time of release.<ref name=USBCReleaseRatioAndEntryAngle/> This ratio continually decreases throughout the ball's travel until it reaches exactly 1.0 when full traction is achieved upon entering the roll phase.<ref name=USBCReleaseRatioAndEntryAngle/> A too-''high'' release ratio |
''[[Glossary of bowling#Release ratio|Release ratio]]'' denotes the ratio of the ball's forward (translational) speed to its rev rate (rotational speed) at time of release.<ref name=USBCReleaseRatioAndEntryAngle/> This ratio continually decreases throughout the ball's travel until it reaches exactly 1.0 when full traction is achieved upon entering the roll phase.<ref name=USBCReleaseRatioAndEntryAngle/> A too-''high'' release ratio, also known as a ''speed-dominant'' release, causes the ball to reach the pins while still in the hook phase, resulting in a shallow [[Glossary of bowling#Angle of entry|angle of entry]] that permits ball deflection and resultant leaves of the 10-pin, while a too-''low'' release ratio, also called a ''rev-dominant'' release, causes the ball to enter the roll phase before reaching the pins, sacrificing power to friction that would ideally be delivered to the pins to enhance [[Glossary of bowling#Pin scatter|pin scatter]].<ref name=USBCReleaseRatioAndEntryAngle/> Ball speed and rev rate are said to be ''matched'' if the ball enters the roll phase immediately before impacting the pins, maximizing power imparted to the pins yet helping to provide an entry angle that minimizes ball deflection.<ref name=USBCReleaseRatioAndEntryAngle>• {{cite web |last1=O'Keefe |first1=Bryan |title=Bowling Release Ratio |url=https://www.usbcbowlingacademy.com/video/bowling-release-ratio-006859/ |website=usbcbowlingacademy.com |archive-url=https://web.archive.org/web/20160402000022/https://www.usbcbowlingacademy.com/video/bowling-release-ratio-006859/ |archive-date=April 2, 2016 |date=2015 |url-status=live}} (date is approximate) <br />• {{cite web |title=Adjusting Entry Angle |url=https://www.bowl.com/Source/Source_Home/Adjusting_Entry_Angle/ |website=bowl.com (United States Bowling Congress, USBC) |archive-url=https://web.archive.org/web/20170417014440/https://www.bowl.com/Source/Source_Home/Adjusting_Entry_Angle/ |archive-date=April 17, 2017 |date=2015 |url-status=live}} (date is approximate)</ref> |
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| caption3 = Bowling ball motion is affected by various characteristics of delivery, as discussed by, for example, Freeman & Hatfield (2018).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Ball motion is determined by a complex interaction of a variety of factors. |
| caption3 = Bowling ball motion is affected by various characteristics of delivery, as discussed by, for example, Freeman & Hatfield (2018).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Ball motion is determined by a complex interaction of a variety of factors. |
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Various characteristics of ball delivery affect a ball's motion throughout its skid, hook and roll phases.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} The particular way in which energy is imparted to a ball—with varying proportions of that energy divided among ball speed, axis control and rev rate—determines the ball's motion.<ref name=BowlingThisMonthImprovingRelease2019>{{cite magazine |last1=Rose |first1=Tyrel |title=Improving Your Release / Tools, techniques, and practice drills for developing a more effective release |url=https://www.bowlingthismonth.com/bowling-tips/improving-your-release/?contactId=58283&linkType=freeArticle |magazine=Bowling This Month |archive-url=https://web.archive.org/web/20190405050019/https://www.bowlingthismonth.com/bowling-tips/improving-your-release/?contactId=58283&linkType=freeArticle |archive-date=April 5, 2019 |date=2019|url-status=live }}</ref> The following discussion considers delivery characteristics separately, with the understanding that ball motion is determined by a complex interaction of a variety of factors.<ref name=BowlingBallComBallMotion_20161229>{{cite web |title=Your Bowling Ball Motion |url=https://www.bowlingball.com/BowlVersity/your-bowling-ball-motion | |
Various characteristics of ball delivery affect a ball's motion throughout its skid, hook and roll phases.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} The particular way in which energy is imparted to a ball—with varying proportions of that energy divided among ball speed, axis control and rev rate—determines the ball's motion.<ref name=BowlingThisMonthImprovingRelease2019>{{cite magazine |last1=Rose |first1=Tyrel |title=Improving Your Release / Tools, techniques, and practice drills for developing a more effective release |url=https://www.bowlingthismonth.com/bowling-tips/improving-your-release/?contactId=58283&linkType=freeArticle |magazine=Bowling This Month |archive-url=https://web.archive.org/web/20190405050019/https://www.bowlingthismonth.com/bowling-tips/improving-your-release/?contactId=58283&linkType=freeArticle |archive-date=April 5, 2019 |date=2019|url-status=live }}</ref> The following discussion considers delivery characteristics separately, with the understanding that ball motion is determined by a complex interaction of a variety of factors.<ref name=BowlingBallComBallMotion_20161229>{{cite web |title=Your Bowling Ball Motion |url=https://www.bowlingball.com/BowlVersity/your-bowling-ball-motion |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20170209030127/https://www.bowlingball.com/BowlVersity/your-bowling-ball-motion |archive-date=February 9, 2017 |date=December 29, 2016 |url-status=live }}</ref><ref name=BowlingBallCom_Variables_20160418>{{cite web |title=Variables You Encounter When Bowling |url=https://www.bowlingball.com/bowlversity/variables-you-encounter-when-bowling |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20161012204113/http://www.bowlingball.com/bowlversity/variables-you-encounter-when-bowling |archive-date=October 12, 2016 |date=April 18, 2016 |url-status=live}}</ref> |
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Greater ball speeds give the ball ''less time'' to hook, thus reducing observed hook though imparting more kinetic energy to the pins; conversely, slower speeds allow more time for greater hook though reducing kinetic energy.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
Greater ball speeds give the ball ''less time'' to hook, thus reducing observed hook though imparting more kinetic energy to the pins; conversely, slower speeds allow more time for greater hook though reducing kinetic energy.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
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Greater rev rates cause the ball to experience more frictional lane contact per revolution and thus (assuming non-zero axis rotation) greater and earlier hook (less "length"— which is the distance from the foul line to the breakpoint at which hooking is maximum); conversely, smaller rev rates cause less frictional engagement and allow the ball to hook less and later (more "length").{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
Greater rev rates cause the ball to experience more frictional lane contact per revolution and thus (assuming non-zero axis rotation) greater and earlier hook (less "length"— which is the distance from the foul line to the breakpoint at which hooking is maximum); conversely, smaller rev rates cause less frictional engagement and allow the ball to hook less and later (more "length").{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
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Analysis of the influence of ''axis rotation'' (sometimes called ''side rotation'') is more complex: There is a degree of axis rotation—generally 25° to 35° and varying with ball speed and rev rate—that may be considered optimal in that hook is maximized; however, this optimum axis rotation also causes minimal length.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Specifically, Freeman & Hatfield (2018) report optimal axis rotation to be '''''arcsin{{nbsp}}(ωr/v)''''' where ''ω'' is rev rate (radians/sec), ''r'' is ball radius (m), and ''v'' is ball speed (m/s).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Below and above optimal axis rotation, more length and less hook are encountered, with greater-than-optimal axis rotation causing a sharper hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
Analysis of the influence of ''axis rotation'' (sometimes called ''side rotation'') is more complex: There is a degree of axis rotation—generally 25° to 35° and varying with ball speed and rev rate—that may be considered optimal in that hook is maximized; however, this optimum axis rotation also causes minimal length.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Specifically, Freeman & Hatfield (2018) report optimal axis rotation to be '''''arcsin{{nbsp}}(ωr/v)''''' where ''ω'' is rev rate (radians/sec), ''r'' is ball radius (m), and ''v'' is ball speed (m/s).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Below and above optimal axis rotation, more length and less hook are encountered, with greater-than-optimal axis rotation causing a sharper hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} Another source states that strictly behind-the-ball release (0° axis rotation) causes an end-over-end rotation, with early hooking, while a release with large side rotation causes greater [[Glossary of bowling#length|length]] before hooking.<ref name=BBcom_20111222>{{cite web |title=Being Able To Adjust Your Axis Rotation Is A Tool Worth Having |url=https://www.bowlingball.com/bowlversity/degrees-of-separation-being-able-to-adjust-your-axis-rotation-is-a-tool-worth-having |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20210305101353/https://www.bowlingball.com/bowlversity/degrees-of-separation-being-able-to-adjust-your-axis-rotation-is-a-tool-worth-having |archive-date=March 5, 2021 |date=December 22, 2011 |url-status=live}}</ref> |
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Greater degrees of initial (at-the-foul-line) axis tilt cause the ball to rotate on smaller-circumference "tracks" (rings on the ball at which it contacts the lane on each revolution), thus reducing the amount of frictional contact to provide greater length and less hook; conversely, smaller degrees of axis tilt involve larger-circumference tracks with more frictional contact per revolution, thus providing less length and more hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
Greater degrees of initial (at-the-foul-line) axis tilt cause the ball to rotate on smaller-circumference "tracks" (rings on the ball at which it contacts the lane on each revolution), thus reducing the amount of frictional contact to provide greater length and less hook; conversely, smaller degrees of axis tilt involve larger-circumference tracks with more frictional contact per revolution, thus providing less length and more hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 13 ("Create a Bowler's Tool Kit") }} |
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====Effect of coverstock, core and layout on ball motion==== |
====Effect of coverstock, core and layout on ball motion==== |
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[[File:20181224 Influences on Bowling Ball Motion.png | thumb|right | upright=1.5 | Bowling ball motion is affected by ball design, as discussed by, for example, Freeman & Hatfield (2018).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }}{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?") }} See also the USBC ball motion study by Stremmel, Ridenour & Stervenz (published ''circa'' 2008).{{sfn |Stremmel |Ridenour | Stervenz |2008 |
[[File:20181224 Influences on Bowling Ball Motion.png | thumb|right | upright=1.5 | Bowling ball motion is affected by ball design, as discussed by, for example, Freeman & Hatfield (2018).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }}{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?") }} See also the USBC ball motion study by Stremmel, Ridenour & Stervenz (published ''circa'' 2008).{{sfn |Stremmel |Ridenour | Stervenz |2008 }}]] |
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| image1 = 20180920 Bowling ball RG and differential.png | caption1 = Commonly cited specifications, RG (radius of gyration) and Differential of RG (indicative of flare potential), plotted on orthogonal axes.<ref name=BowlingBallComRGandDIFF/> Freeman & Hatfield (2018) minimize the contribution of differential to ball motion.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?")}} |
| image1 = 20180920 Bowling ball RG and differential.png | caption1 = Commonly cited specifications, RG (radius of gyration) and Differential of RG (indicative of flare potential), plotted on orthogonal axes.<ref name=BowlingBallComRGandDIFF/> Freeman & Hatfield (2018) minimize the contribution of differential to ball motion.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?")}} |
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| image2 = 20200109 Simulated track flare lines on bowling ball.jpg | caption2 = [[Glossary of bowling#Track flare|Track flare]]—not to be confused with "[[Glossary of bowling#Flare potential|flare potential]]"—is progression of the ball's oil [[Glossary of bowling#Tracks|track]] (simulated in blue) reflecting migration of the ball's [[Rotation around a fixed axis|axis of rotation]] on successive revolutions. |
| image2 = 20200109 Simulated track flare lines on bowling ball.jpg | caption2 = [[Glossary of bowling#Track flare|Track flare]]—not to be confused with "[[Glossary of bowling#Flare potential|flare potential]]"—is progression of the ball's oil [[Glossary of bowling#Tracks|track]] (simulated in blue) reflecting migration of the ball's [[Rotation around a fixed axis|axis of rotation]] on successive revolutions. |
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Various characteristics of ball core structure and coverstock composition affect a ball's motion throughout its skid, hook and roll phases.<ref name=BTM_Balls_20170331/>{{sfn |Stremmel |Ridenour | Stervenz |2008 |p=3 }} Such motion is largely (about 75%<ref name=NationalBowlingAcademy_202208>{{cite web |last1=McEwan |first1=Jason |title=A Guide to Bowling Ball Cores, RG, Differential, and Coverstock |url=https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |website=National Bowling Academy |archive-url=https://web.archive.org/web/20220825203526/https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |archive-date=25 August 2022 |date=August 2022 |url-status=live }}</ref> |
Various characteristics of ball core structure and coverstock composition affect a ball's motion throughout its skid, hook and roll phases.<ref name=BTM_Balls_20170331/>{{sfn |Stremmel |Ridenour | Stervenz |2008 |p=3 }}<ref name=NatBowlAcad_20240513>{{cite web |title=Picking a New Bowling Ball for the Average Bowler |url=https://www.nationalbowlingacademy.com/post/picking-a-new-bowling-ball-for-the-average-bowler/ |publisher=National Bowling Academy |archive-url=https://web.archive.org/web/20240719002815/https://www.nationalbowlingacademy.com/post/picking-a-new-bowling-ball-for-the-average-bowler/ |archive-date=July 19, 2024 |date=May 13, 2024 |url-status=live}}</ref> Such motion is largely (about 75%)<ref name=NationalBowlingAcademy_202208>{{cite web |last1=McEwan |first1=Jason |title=A Guide to Bowling Ball Cores, RG, Differential, and Coverstock |url=https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |website=National Bowling Academy |archive-url=https://web.archive.org/web/20220825203526/https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |archive-date=25 August 2022 |date=August 2022 |url-status=live }}</ref><ref name=NationalBowlingAcad_2022>{{cite web |last1=McEwen |first1=Jason |title=A Guide to Bowling Ball Cores, RG, Differential, and Coverstock |url=https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |publisher=National Bowling Academy |archive-url=https://web.archive.org/web/20230321235230/https://www.nationalbowlingacademy.com/post/a-guide-to-bowling-ball-cores-rg-differential-and-coverstock/ |archive-date=March 21, 2023 |date=2022 |url-status=live}}</ref> governed by the lane's [[friction]]al interaction with the ball, which exhibits both ''chemical'' friction characteristics and ''physical'' friction characteristics.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} Also, the ball's internal structure—especially the density, shape (symmetric vs. asymmetric), and orientation of its core (also called "weight block") relative to the ball's axis of rotation—substantially affect ball motion.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} |
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A "dull" (rough) ball surface, having spikes and pores,{{sfn |Stremmel |Ridenour | Stervenz |2008 |p=8 }} provides greater friction in the oil-covered front end of the lane but reduced frictional contact in the dry back end of the lane, and thus enables an earlier hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} In contrast, a "gloss" (smooth) ball surface tends to glide atop oil on the front end but establishes ''greater'' frictional contact in the dry back end, thus promoting a sharper hook downlane |
A "dull" (rough) ball surface, having spikes and pores,{{sfn |Stremmel |Ridenour | Stervenz |2008 |p=8 }} provides greater friction in the oil-covered front end of the lane but reduced frictional contact in the dry back end of the lane, and thus enables an earlier hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} In contrast, a "gloss" (smooth) ball surface tends to glide atop oil on the front end but establishes ''greater'' frictional contact in the dry back end, thus promoting a sharper hook downlane,{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} such as in the "[[Glossary of bowling#Skid/flip|skid/flip]]" ball path.<ref name=BBcom_20100907>{{cite web |last1=Carrubba |first1=Rich |title=How To Find A Skid-Flip Bowling Ball |url=https://www.bowlingball.com/bowlversity/how-to-find-a-skid-flip-bowling-ball |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20210226212958/https://www.bowlingball.com/bowlversity/how-to-find-a-skid-flip-bowling-ball |archive-date=February 26, 2021 |date=September 7, 2010 |url-status=live}}</ref> Accordingly, because different lane conditions and bowler styles favor different hook profiles, there is no single "best" surface.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} |
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A 2005-2008 [[United States Bowling Congress|USBC]] Ball Motion Study found that the ball design factors that most contributed to ball motion were the microscopic "spikes" and pores on the ball's surface (considered part of chemical frictional characteristics), the respective coefficients of friction between ball and lane in the oiled and dry parts of the lane, and the ball's oil absorption rate, followed in dominance by certain characteristics of the ball's core (mainly radius of gyration, and total differential).{{sfn |Stremmel |Ridenour |Stervenz |2008 |
A 2005-2008 [[United States Bowling Congress|USBC]] Ball Motion Study found that the ball design factors that most contributed to ball motion were the microscopic "spikes" and pores on the ball's surface (considered part of chemical frictional characteristics), the respective coefficients of friction between ball and lane in the oiled and dry parts of the lane, and the ball's oil absorption rate, followed in dominance by certain characteristics of the ball's core (mainly radius of gyration, and total differential).{{sfn |Stremmel |Ridenour |Stervenz |2008 }} Freeman and Hatfield (2018) explain that in most circumstances it is chemical friction—controlled by the manufacturer's proprietary coverstock formulation governing its "stickiness"—that primarily determines ball motion.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} Further, surface finish—modifiable by sandpaper, polish and the like—is also a material factor.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 8 ("Why Does My Ball Hook?") }} |
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Though manufacturer literature often specifies ''track flare''—exhibited by successive tracks of oil in a "bowtie" pattern and caused by RG differential—the [[United States Bowling Congress|USBC]] ball motion study showed flare's influence to be small,{{sfn |Stremmel |Ridenour | Stervenz |2008 |
Though manufacturer literature often specifies ''track flare''—exhibited by successive tracks of oil in a "bowtie" pattern and caused by RG differential—the [[United States Bowling Congress|USBC]] ball motion study showed flare's influence to be small,{{sfn |Stremmel |Ridenour | Stervenz |2008 }} assuming that a minimal threshold of flare exists to present a "dry" surface for successive ball revolutions.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?") }} Similarly, though manufacturer literature often describes specific core shapes, differently-shaped cores can make exactly the same contribution to ball motion if they have the same overall RG characteristics.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 9 ("Track Flare, or Much Ado About Nothing?") }} |
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"Weak" layouts ("pin down": pin between finger and thumb holes) hook sooner but have milder backend reaction, while "strong" layouts ("pin up": pin further from thumb hole than finger holes) enable greater skid lengths and more angular backend reaction.<ref name=BBdrill201501/><ref name=CTDpinUpDown20170411/> |
"Weak" layouts ("pin down": pin between finger and thumb holes) hook sooner but have milder backend reaction, while "strong" layouts ("pin up": pin further from thumb hole than finger holes) enable greater skid lengths and more angular backend reaction.<ref name=BBdrill201501/><ref name=CTDpinUpDown20170411/> |
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might be concentrated without changing its [[moment of inertia]]".<ref name=USBCtechnicalTerms>{{cite web |title=Technical Terms |url=https://www.bowl.com/uploadedFiles/Equipment_Specs/Information/Updated_Terminology.pdf |website=bowl.com |publisher=United States Bowling Congress |access-date=25 September 2018 |archive-url=https://web.archive.org/web/20180920192721/https://www.bowl.com/uploadedFiles/Equipment_Specs/Information/Updated_Terminology.pdf |archive-date=September 20, 2018 |url-status=live }}</ref> In practice, a higher RG indicates that a ball's mass is distributed more toward its cover—making it "cover heavy"—which tends to make the ball enter the roll phase later (further down the lane).<ref name=BowlingBallComRGandDIFF/> Conversely, a lower RG indicates the ball's mass is distributed more towards its center—making it "center heavy"—which tends to make it enter the roll phase sooner.<ref name=BowlingBallComRGandDIFF/> |
might be concentrated without changing its [[moment of inertia]]".<ref name=USBCtechnicalTerms>{{cite web |title=Technical Terms |url=https://www.bowl.com/uploadedFiles/Equipment_Specs/Information/Updated_Terminology.pdf |website=bowl.com |publisher=United States Bowling Congress |access-date=25 September 2018 |archive-url=https://web.archive.org/web/20180920192721/https://www.bowl.com/uploadedFiles/Equipment_Specs/Information/Updated_Terminology.pdf |archive-date=September 20, 2018 |url-status=live }}</ref> In practice, a higher RG indicates that a ball's mass is distributed more toward its cover—making it "cover heavy"—which tends to make the ball enter the roll phase later (further down the lane).<ref name=BowlingBallComRGandDIFF/> Conversely, a lower RG indicates the ball's mass is distributed more towards its center—making it "center heavy"—which tends to make it enter the roll phase sooner.<ref name=BowlingBallComRGandDIFF/> |
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Differential of RG is the difference between maximum and minimum RGs measured with respect to different axes.<ref name=BowlingBallComRGandDIFF/> Differential indicates the ball's track ''flare potential,'' and contributes to how sharply a ball can [[hook (bowling)|hook]].<ref name=BowlingBallComRGandDIFF/> A higher differential indicates greater track flare potential—more angular motion from the break point to the pocket—and a lower differential indicates lower flare potential and a smoother arc to the hook.<ref name=BowlingBallComRGandDIFF>{{cite web |title=Bowling Ball RG And Differential Range Ratings |url=https://www.bowlingball.com/wordpress/bowling-ball-rg-and-differential-range-ratings-2 | |
Differential of RG is the difference between maximum and minimum RGs measured with respect to different axes.<ref name=BowlingBallComRGandDIFF/> Differential indicates the ball's track ''flare potential,'' and contributes to how sharply a ball can [[hook (bowling)|hook]].<ref name=BowlingBallComRGandDIFF/> A higher differential indicates greater track flare potential—more angular motion from the break point to the pocket—and a lower differential indicates lower flare potential and a smoother arc to the hook.<ref name=BowlingBallComRGandDIFF>{{cite web |title=Bowling Ball RG And Differential Range Ratings |url=https://www.bowlingball.com/wordpress/bowling-ball-rg-and-differential-range-ratings-2 |publisher=BowlingBall.com (Bowlversity educational section) |access-date=25 September 2018 |archive-url=https://web.archive.org/web/20141226063716/https://www.bowlingball.com/wordpress/bowling-ball-rg-and-differential-range-ratings-2 |archive-date=December 26, 2014 | date=2014 |url-status=live}}</ref> |
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The lesser-used ''intermediate differential'' rating (sometimes termed ''mass bias'' rating) quantifies the degree to which a bowling ball core is ''symmetrical'' or ''asymmetrical.''<ref name=BowlingBallComRGandDIFF/> Analytically, ID is defined by the USBC as the "difference in radius of gyration between the Y (high RG) and Z (intermediate RG) axes".<ref name=USBCtechnicalTerms/> In practice, a higher ID indicates greater asymmetry, which causes more area to be created at the break point to cause the ball to respond more quickly to friction than symmetrical balls.<ref name=BowlingBallComRGandDIFF/> |
The lesser-used ''intermediate differential'' rating (sometimes termed ''mass bias'' rating) quantifies the degree to which a bowling ball core is ''symmetrical'' or ''asymmetrical.''<ref name=BowlingBallComRGandDIFF/> Analytically, ID is defined by the USBC as the "difference in radius of gyration between the Y (high RG) and Z (intermediate RG) axes".<ref name=USBCtechnicalTerms/> In practice, a higher ID indicates greater asymmetry, which causes more area to be created at the break point to cause the ball to respond more quickly to friction than symmetrical balls.<ref name=BowlingBallComRGandDIFF/> |
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[[File:20230126 Bowling ball surface textures - grit granularity, skid length, and hook.svg|thumb|upright=1.35 |The texture of ball surfaces—measured in "[[Glossary of bowling#grit|grit]]" of abrasives used—affects ball path (skid distance and hook intensity).<ref name=BBcom_20130204>{{cite web |last1=Carrubba |first1=Rich |title=Bowling Ball Surface Grit Pads |url=https://www.bowlingball.com/BowlVersity/bowling-ball-surface-grit-pads |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20201111234550/https://www.bowlingball.com/BowlVersity/bowling-ball-surface-grit-pads |archive-date=November 11, 2020 |date=February 4, 2013 |url-status=live}}</ref><ref name=BBcom_20120000>{{cite web |last1=Carrubba |first1=Rich |title=BowlVersity Q & A Part 2 / Q. Which are the most effective ranges of grit pads to use when altering bowling ball surfaces? |url=https://www.bowlingball.com/BowlVersity/bowlingball-com-bowlversity-q-a-part-2 |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20150918231608/https://www.bowlingball.com/BowlVersity/bowlingball-com-bowlversity-q-a-part-2 |archive-date=September 18, 2015 |date=2012 |url-status=live }}</ref>]] |
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Informally, a low-differential ball has been likened to one whose core is a spherical object (whose height and width are the same); a high-differential ball has been likened to a tall drinking glass (whose height and width are different); and a high-mass-bias ball has been likened to a tall drinking mug with a handle on the side (which has different widths in different directions).<ref name=BowlingBallBallDynamics2005>{{cite web |title=Ball Dynamics and Hook Potential |url=https://www.bowlingball.com/info/ball-dynamics-and-hook-potential.html |publisher=BowlingBall.com (Bowlversity educational section) |access-date=25 September 2018 |archive-url=https://web.archive.org/web/20051124224223/https://www.bowlingball.com/info/ball-dynamics-and-hook-potential.html |archive-date=November 24, 2005 |date=2005 |url-status=live }}</ref> |
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Higher-friction surfaces (lower grit numbers) cause balls to hook earlier, and lower-friction surfaces (higher grit numbers) cause balls to skid longer before reacting (hooking).<ref name=Bowlversity20160522>{{cite web |title=Understand Your Bowling Ball Reaction |url=https://www.bowlingball.com/bowlversity/understand-your-bowling-ball-reaction?bowlversityarticleid=16512 |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20181202202315/https://www.bowlingball.com/bowlversity/understand-your-bowling-ball-reaction?bowlversityarticleid=16512 |archive-date=December 2, 2018 |date=May 22, 2016 |url-status=live}}</ref> |
Higher-friction surfaces (lower grit numbers) cause balls to hook earlier, and lower-friction surfaces (higher grit numbers) cause balls to skid longer before reacting (hooking).<ref name=Bowlversity20160522>{{cite web |title=Understand Your Bowling Ball Reaction |url=https://www.bowlingball.com/bowlversity/understand-your-bowling-ball-reaction?bowlversityarticleid=16512 |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20181202202315/https://www.bowlingball.com/bowlversity/understand-your-bowling-ball-reaction?bowlversityarticleid=16512 |archive-date=December 2, 2018 |date=May 22, 2016 |url-status=live}}</ref> |
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[[File:1895 Bowling lane cross section.jpg |thumb|upright=1.5 |Adjusting screws at the sides of bowling lanes in this 1895 cross-sectional diagram show the recognized importance of controlling lane [[Glossary of bowling#Topography|topography]] to provide a flat and level surface for repeatable ball motion.<ref name=NarragansettMachine_Gutenberg_1895>{{cite web |title=Bowling Catalog E |url=http://www.gutenberg.org/files/57337/57337-h/57337-h.htm |website=Gutenberg.org |publisher=Narragansett Machine Company |archive-url=https://web.archive.org/web/20180701141541/http://www.gutenberg.org/files/57337/57337-h/57337-h.htm |archive-date=July 1, 2018 |date=1895 |url-status=live}} [[Project Gutenberg]] release date: June 16, 2018.</ref>]] |
[[File:1895 Bowling lane cross section.jpg |thumb|upright=1.5 |Adjusting screws at the sides of bowling lanes in this 1895 cross-sectional diagram show the recognized importance of controlling lane [[Glossary of bowling#Topography|topography]] to provide a flat and level surface for repeatable ball motion.<ref name=NarragansettMachine_Gutenberg_1895>{{cite web |title=Bowling Catalog E |url=http://www.gutenberg.org/files/57337/57337-h/57337-h.htm |website=Gutenberg.org |publisher=Narragansett Machine Company |archive-url=https://web.archive.org/web/20180701141541/http://www.gutenberg.org/files/57337/57337-h/57337-h.htm |archive-date=July 1, 2018 |date=1895 |url-status=live}} [[Project Gutenberg]] release date: June 16, 2018.</ref>]] |
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The phenomenon of ''lane transition'' occurs when balls remove oil from the lane as they pass, and deposit some of that oil on originally dry parts of the lane.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }}<ref name=BowlingBallCom_LaneTransition2015>{{cite web |title=Changing Lane Oil Conditions |url=https://www.bowlingball.com/bowlversity/changing-lane-oil-conditions | |
The phenomenon of ''lane transition'' occurs when balls remove oil from the lane as they pass, and deposit some of that oil on originally dry parts of the lane.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }}<ref name=BowlingBallCom_LaneTransition2015>{{cite web |title=Changing Lane Oil Conditions |url=https://www.bowlingball.com/bowlversity/changing-lane-oil-conditions |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20150918190617/http://www.bowlingball.com/BowlVersity/changing-lane-oil-conditions |archive-date=September 18, 2015 |date=2015 |url-status=live}}</ref> The process of oil removal, commonly called ''breakdown,'' forms dry paths that subsequently cause balls to experience increased friction and to hook sooner.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }}<ref name=BowlingBallCom_LaneTransition2015/> Conversely, the process of oil deposition, commonly called ''carry down,'' occurs when balls form oil tracks in formerly dry areas, tracks that subsequently cause balls to experience less friction and delayed hook.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }}<ref name=BowlingBallCom_LaneTransition2015/> Balls tend to "roll out" (hook sooner but hook less) in response to breakdown, and, conversely, tend to skid longer (and hook later) in response to carry down—both resulting in light hits.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 16 ("Advanced Considerations") }} Breakdown is influenced by the oil absorption characteristics and rev rates of the balls that were previously rolled,{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} and carry down is mitigated by modern balls having substantial track flare.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 16 ("Advanced Considerations") }} |
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Lane materials with softer surfaces such as wood engage the ball with more friction and thus provide more hook potential, while harder surfaces like synthetic compositions provide less friction and thus provide less hook potential.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} |
Lane materials with softer surfaces such as wood engage the ball with more friction and thus provide more hook potential, while harder surfaces like synthetic compositions provide less friction and thus provide less hook potential.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} |
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Higher-[[viscosity]] lane oils (those with thicker consistency) engage balls with more friction and thus cause slower speeds and shorter length but provide more hook potential and reduced lane transition; conversely, lane oils of lower viscosity (thinner consistency) are more slippery and thus support greater speeds and length but offer less hook potential and allow faster lane transition.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} Various factors influence an oil's native viscosity, including temperature (with higher temperatures causing the oil to be thinner) and humidity (variations of which can cause crowning and cupping of the lane surface).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} Also, high humidity increases friction that reduces skid distance so the ball tends to hook sooner.<ref name=BowlingBallCom20160628AdjustPair-Humidity>{{cite web |title=Bowling Lane Adjusting From Pair To Pair |url=https://www.bowlingball.com/BowlVersity/bowling-lane-adjusting-from-pair-to-pair | |
Higher-[[viscosity]] lane oils (those with thicker consistency) engage balls with more friction and thus cause slower speeds and shorter length but provide more hook potential and reduced lane transition; conversely, lane oils of lower viscosity (thinner consistency) are more slippery and thus support greater speeds and length but offer less hook potential and allow faster lane transition.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} Various factors influence an oil's native viscosity, including temperature (with higher temperatures causing the oil to be thinner) and humidity (variations of which can cause crowning and cupping of the lane surface).{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} Also, high humidity increases friction that reduces skid distance so the ball tends to hook sooner.<ref name=BowlingBallCom20160628AdjustPair-Humidity>{{cite web |title=Bowling Lane Adjusting From Pair To Pair |url=https://www.bowlingball.com/BowlVersity/bowling-lane-adjusting-from-pair-to-pair |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20161031145511/https://www.bowlingball.com/BowlVersity/bowling-lane-adjusting-from-pair-to-pair |archive-date=October 31, 2016 |date=June 28, 2016 |url-status=live }}</ref> |
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The lanes' physical topography—hills and valleys that diverge from an ideal planar surface—can substantially and unpredictably affect ball motion, even if the lane is within permissible tolerances.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} |
The lanes' physical topography—hills and valleys that diverge from an ideal planar surface—can substantially and unpredictably affect ball motion, even if the lane is within permissible tolerances.{{sfn |Freeman |Hatfield |2018 |loc=Chapter 14 ("Applying Your Tools") }} |
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==Duckpin balls== |
==Duckpin balls== |
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[[File:20190609 Duckpin bowling ball in hand.jpg|thumb|right |upright=1.5 | A duckpin bowling ball in an adult hand |
[[File:20190609 Duckpin bowling ball in hand.jpg|thumb|right |upright=1.5 | A duckpin bowling ball in an adult hand]] |
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[[Duckpin bowling]] balls are regulated to be from {{convert|4.75|–|5.00|in|cm}} in diameter and to weigh between {{convert|3|lb|6|oz|kg}} and {{convert|3|lb|12|oz|kg}}.<ref name=Paramount2017/> They lack finger holes.<ref name=Paramount2017/> Though duckpin balls are slightly larger than candlepin balls, they have less than 60% the diameter of ten-pin balls, to match the smaller size of duckpins.<ref name=Paramount2017>{{cite web |title=Duckpin Bowling |url=https://www.paramountindustriesinc.com/pages/duckpin-bowling |website=paramountindustriesinc.com |archive-url=https://web.archive.org/web/20170411214139/https://www.paramountindustriesinc.com/pages/duckpin-bowling |archive-date=April 11, 2017 |date=2017 |url-status=live }}</ref> Duckpin balls are sometimes used for scaled-down ten-pin bowling lanes installed in [[arcade game|arcades]] and other [[Amusement arcade|amusement facilities]].{{Citation needed|date=July 2019}} |
[[Duckpin bowling]] balls are regulated to be from {{convert|4.75|–|5.00|in|cm}} in diameter and to weigh between {{convert|3|lb|6|oz|kg}} and {{convert|3|lb|12|oz|kg}}.<ref name=Paramount2017/> They lack finger holes.<ref name=Paramount2017/> Though duckpin balls are slightly larger than candlepin balls, they have less than 60% the diameter of ten-pin balls, to match the smaller size of duckpins.<ref name=Paramount2017>{{cite web |title=Duckpin Bowling |url=https://www.paramountindustriesinc.com/pages/duckpin-bowling |website=paramountindustriesinc.com |archive-url=https://web.archive.org/web/20170411214139/https://www.paramountindustriesinc.com/pages/duckpin-bowling |archive-date=April 11, 2017 |date=2017 |url-status=live }}</ref> Duckpin balls are sometimes used for scaled-down ten-pin bowling lanes installed in [[arcade game|arcades]] and other [[Amusement arcade|amusement facilities]].{{Citation needed|date=July 2019}} |
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==External links== |
==External links== |
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* {{cite magazine |title=Bowling Balls: An In-Depth Overview |url=https://www.bowlingthismonth.com/bowling-balls/ |magazine=Bowling This Month |archive-url=https://web.archive.org/web/20190412221716/https://www.bowlingthismonth.com/bowling-balls/ |archive-date=April 12, 2019 |date=March 31, 2017 |url-status=live }} |
* {{cite magazine |title=Bowling Balls: An In-Depth Overview |url=https://www.bowlingthismonth.com/bowling-balls/ |magazine=Bowling This Month |archive-url=https://web.archive.org/web/20190412221716/https://www.bowlingthismonth.com/bowling-balls/ |archive-date=April 12, 2019 |date=March 31, 2017 |url-status=live }} |
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* {{cite web |last1= |
* {{cite web |last1=Carruba |first1=Rich |title=How Bowling Balls Are Made |url=https://www.bowlingball.com/bowlversity/how-bowling-balls-are-made |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20230324193548/https://www.bowlingball.com/bowlversity/how-bowling-balls-are-made |archive-date=24 March 2023 |date=2011 |url-status=live}} |
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* {{cite web |last1=Carrubba |first1=Rich |title=Bowling Ball Evolution |url=https://www.bowlingball.com/BowlVersity/bowling-ball-evolution |publisher=BowlingBall.com (Bowlversity educational section) |archive-url=https://web.archive.org/web/20180917215354/https://www.bowlingball.com/BowlVersity/bowling-ball-evolution |archive-date=September 17, 2018 |date=June 2012 |url-status=live }} |
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* {{cite magazine |last1=Horaczek |first1=Stan |title=The insides of pro bowling balls will make your head spin |url=https://www.popsci.com/story/technology/bowling-ball-insides-photos/ |magazine=Popular Science |date=July 27, 2020 |archive-url=https://web.archive.org/web/20210827005550/https://www.popsci.com/story/technology/bowling-ball-insides-photos/ |archive-date=August 27, 2021 |url-status=live }} |
* {{cite magazine |last1=Horaczek |first1=Stan |title=The insides of pro bowling balls will make your head spin |url=https://www.popsci.com/story/technology/bowling-ball-insides-photos/ |magazine=Popular Science |date=July 27, 2020 |archive-url=https://web.archive.org/web/20210827005550/https://www.popsci.com/story/technology/bowling-ball-insides-photos/ |archive-date=August 27, 2021 |url-status=live }} |
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* Muller, Derek and Zhang, Emily (September 25, 2021). [https://www.youtube.com/watch?v=aFPJf-wKTd0 "The Fascinating Physics of Bowling"], [[Derek Muller|Veritasium]]. |
* Muller, Derek and Zhang, Emily (September 25, 2021). [https://www.youtube.com/watch?v=aFPJf-wKTd0 "The Fascinating Physics of Bowling"], [[Derek Muller|Veritasium]]. |
Latest revision as of 17:17, 14 November 2024
A bowling ball is a hard spherical ball used to knock down bowling pins in the sport of bowling.
Balls used in ten-pin bowling and American nine-pin bowling traditionally have holes for two fingers and the thumb. Balls used in five-pin bowling, candlepin bowling, duckpin bowling, and European nine-pin bowling have no holes, and are small enough to be held in the palm of the hand.
Ten-pin balls
[edit]Specifications
[edit](fingers insert only to first knuckle)
The USBC and World Bowling promulgate bowling ball specifications. USBC specifications include physical requirements for weight (≤16 pounds (7.3 kg)), diameter (8.500 inches (21.59 cm)—8.595 inches (21.83 cm)), surface hardness, surface roughness, hole drilling limitations (example: a single balance hole including the thumb hole for "two-handed" bowlers[3]), balance, plug limitations, and exterior markings (structural and commercial), as well as requirements for dynamic performance characteristics such as radius of gyration (RG; 2.46—2.80), RG differential (≤0.06), and coefficient of friction (≤0.32).[4] The USBC banned weight holes (balance holes) in competition, effective August 1, 2020, to prevent their changing ball dynamics.[5] The USBC permits three ounces (85 grams) of static side weight and three ounces (85 grams) of top weight. These figures are up from one ounce (28 grams) following the August 1, 2020 rule change.[6]
Coverstock technology
[edit]Bowling balls were made of lignum vitae (hardwood) until the 1905 introduction of rubber balls.[2] Polyester ("plastic") balls were introduced in 1959 and, despite developing less hook-generating lane friction than rubber balls, by the 1970s plastic dominated over rubber balls.[2] Briefly, "soaker" ball technology—involving softening coverstocks to achieve greater hook—were used, until rules for minimum hardness were implemented.[8] The early-1980s development of polyurethane ("urethane") balls developed more friction with the newly developed polyurethane lane finishes of the day, sparking the evolution of coverstock technology to pursue ever-stronger hooks with correspondingly higher entry angles.[2][9]
The early 1990s brought development of reactive resin ("reactive") balls by introducing additives in urethane surface materials to create microscopic oil-absorbing pores that increase the "tackiness" that enhances traction.[2][7][9] In the "particle-enhanced" balls developed in the late 1990s, microscopic particles embedded in reactive coverstocks reach through oil lane coatings to provide even greater traction.[2][7] Ball manufacturers developed closely guarded proprietary blends including ground-up material such as glass, ceramic or rubber, to enhance friction.[10]
Within the reactive category are solid reactive coverstocks (having the greatest amount of microscopic pores), pearl reactive coverstocks (including mica additives that enhance reaction on dry lane surfaces), hybrid reactive coverstocks (combining the mid-lane reaction of solid coverstocks and the back-end reaction of pearl coverstocks), and particle coverstocks (including microscopic silica particles, favored for use on heavy oil volumes).[2][9][11]
Hook potential has increased so much that dry lane conditions or certain spare shots sometimes cause bowlers to use plastic or urethane balls, to purposely avoid the larger hook provided by reactive technology.[2][7]
Layout and grip
[edit]
A ball's drilling layout refers to how and where holes are drilled, in relation to the ball's locator pin and mass bias (MB) marker.[9][12] Layout is determined with reference to each bowler's positive axis point (PAP — the pocket end of the ball's initial axis of rotation).[13] "Pin down" layouts place the pin between the finger holes and the thumb hole, while "pin up" layouts place the pin further from the thumb hole than the finger holes (see photos).[12][14] Bowling ball motion is influenced by how far the pin and the mass bias (MB) are from the PAP, the distances determining track flare.[13] Track flare—the sequence of oil rings showing migration of the ball's axis on successive revolutions through the oil pattern—is popularly thought to influence entry angle,[13] but Freeman & Hatfield (2018) discount its contribution to ball motion.[15]
Holes may be drilled for a conventional grip (fingers inserted to the second knuckle as with "house balls"), a fingertip grip (fingers inserted only to the first knuckle, enabling greater rev-generating torque), or less standard grips such as the Sarge Easter grip (ring finger inserted to the second knuckle but middle finger inserted only to the first knuckle).[16] Many bowlers using the so-called "two-handed delivery" (which is still a one-handed release) do not insert their thumbs, thus allowing their fingers to impart even more torque than the fingertip grip.[16]
Finger inserts and thumb slugs are custom-fit urethane tubes inserted into the drilled holes, generally for balls with a fingertip grip.[17] Finger inserts enhance the torque provided by the fingers after the thumb exits the ball.[17]
Ball motion
[edit]A complex interaction of a variety of factors influences ball motion and its effect on scoring results.[18][19][20][21][22] The factors may be categorized as the bowler's delivery, the bowling ball's design, and the condition of the lane.
Stages of ball motion
[edit]Bowling ball motion[20] is commonly broken down into sequential skid, hook, and roll phases.[23][24] As the ball travels down the lane in the skid and hook phases, frictional contact with the lane causes the ball's forward (translational) speed to continually decrease, but to continually increase its rev rate (rotational speed).[25] Especially as the ball encounters greater friction in the last ≈20 feet (approximate) of the lane, the ball's axis rotation (side rotation) causes the ball to hook away from its original direction.[25] Concurrently, lane friction continually decreases the angle of axis rotation until it exactly matches the direction of the ball's forward motion, and rev rate (rotational speed) increases until it exactly matches the ball's forward speed: full traction is achieved and the ball enters the roll phase in which forward speed continues to decrease.[25]
Effect of delivery characteristics on ball motion
[edit]Release ratio denotes the ratio of the ball's forward (translational) speed to its rev rate (rotational speed) at time of release.[26] This ratio continually decreases throughout the ball's travel until it reaches exactly 1.0 when full traction is achieved upon entering the roll phase.[26] A too-high release ratio, also known as a speed-dominant release, causes the ball to reach the pins while still in the hook phase, resulting in a shallow angle of entry that permits ball deflection and resultant leaves of the 10-pin, while a too-low release ratio, also called a rev-dominant release, causes the ball to enter the roll phase before reaching the pins, sacrificing power to friction that would ideally be delivered to the pins to enhance pin scatter.[26] Ball speed and rev rate are said to be matched if the ball enters the roll phase immediately before impacting the pins, maximizing power imparted to the pins yet helping to provide an entry angle that minimizes ball deflection.[26]
Various characteristics of ball delivery affect a ball's motion throughout its skid, hook and roll phases.[27] The particular way in which energy is imparted to a ball—with varying proportions of that energy divided among ball speed, axis control and rev rate—determines the ball's motion.[28] The following discussion considers delivery characteristics separately, with the understanding that ball motion is determined by a complex interaction of a variety of factors.[21][22]
Greater ball speeds give the ball less time to hook, thus reducing observed hook though imparting more kinetic energy to the pins; conversely, slower speeds allow more time for greater hook though reducing kinetic energy.[27]
Greater rev rates cause the ball to experience more frictional lane contact per revolution and thus (assuming non-zero axis rotation) greater and earlier hook (less "length"— which is the distance from the foul line to the breakpoint at which hooking is maximum); conversely, smaller rev rates cause less frictional engagement and allow the ball to hook less and later (more "length").[27]
Analysis of the influence of axis rotation (sometimes called side rotation) is more complex: There is a degree of axis rotation—generally 25° to 35° and varying with ball speed and rev rate—that may be considered optimal in that hook is maximized; however, this optimum axis rotation also causes minimal length.[27] Specifically, Freeman & Hatfield (2018) report optimal axis rotation to be arcsin (ωr/v) where ω is rev rate (radians/sec), r is ball radius (m), and v is ball speed (m/s).[27] Below and above optimal axis rotation, more length and less hook are encountered, with greater-than-optimal axis rotation causing a sharper hook.[27] Another source states that strictly behind-the-ball release (0° axis rotation) causes an end-over-end rotation, with early hooking, while a release with large side rotation causes greater length before hooking.[29]
Greater degrees of initial (at-the-foul-line) axis tilt cause the ball to rotate on smaller-circumference "tracks" (rings on the ball at which it contacts the lane on each revolution), thus reducing the amount of frictional contact to provide greater length and less hook; conversely, smaller degrees of axis tilt involve larger-circumference tracks with more frictional contact per revolution, thus providing less length and more hook.[27]
Loft—the distance past the foul line at which the ball first contacts the lane—determines the effective length of the lane as experienced by the ball: greater loft distances effectively shorten the lane and provide greater length, while smaller loft distances engage the lane earlier and cause an earlier hook.[27]
Effect of coverstock, core and layout on ball motion
[edit]Various characteristics of ball core structure and coverstock composition affect a ball's motion throughout its skid, hook and roll phases.[9][23][32] Such motion is largely (about 75%)[33][34] governed by the lane's frictional interaction with the ball, which exhibits both chemical friction characteristics and physical friction characteristics.[25] Also, the ball's internal structure—especially the density, shape (symmetric vs. asymmetric), and orientation of its core (also called "weight block") relative to the ball's axis of rotation—substantially affect ball motion.[25]
A "dull" (rough) ball surface, having spikes and pores,[35] provides greater friction in the oil-covered front end of the lane but reduced frictional contact in the dry back end of the lane, and thus enables an earlier hook.[25] In contrast, a "gloss" (smooth) ball surface tends to glide atop oil on the front end but establishes greater frictional contact in the dry back end, thus promoting a sharper hook downlane,[25] such as in the "skid/flip" ball path.[36] Accordingly, because different lane conditions and bowler styles favor different hook profiles, there is no single "best" surface.[25]
A 2005-2008 USBC Ball Motion Study found that the ball design factors that most contributed to ball motion were the microscopic "spikes" and pores on the ball's surface (considered part of chemical frictional characteristics), the respective coefficients of friction between ball and lane in the oiled and dry parts of the lane, and the ball's oil absorption rate, followed in dominance by certain characteristics of the ball's core (mainly radius of gyration, and total differential).[30] Freeman and Hatfield (2018) explain that in most circumstances it is chemical friction—controlled by the manufacturer's proprietary coverstock formulation governing its "stickiness"—that primarily determines ball motion.[25] Further, surface finish—modifiable by sandpaper, polish and the like—is also a material factor.[25]
Though manufacturer literature often specifies track flare—exhibited by successive tracks of oil in a "bowtie" pattern and caused by RG differential—the USBC ball motion study showed flare's influence to be small,[30] assuming that a minimal threshold of flare exists to present a "dry" surface for successive ball revolutions.[15] Similarly, though manufacturer literature often describes specific core shapes, differently-shaped cores can make exactly the same contribution to ball motion if they have the same overall RG characteristics.[15]
"Weak" layouts ("pin down": pin between finger and thumb holes) hook sooner but have milder backend reaction, while "strong" layouts ("pin up": pin further from thumb hole than finger holes) enable greater skid lengths and more angular backend reaction.[12][14]
Manufacturers commonly cite specifications relating to a bowling ball's core, include radius of gyration (RG), differential of RG (commonly abbreviated differential), and intermediate differential (also called mass bias).[31][9]
Analytically, the United States Bowling Congress defines RG as "the distance from the axis of rotation at which the total mass of a body might be concentrated without changing its moment of inertia".[38] In practice, a higher RG indicates that a ball's mass is distributed more toward its cover—making it "cover heavy"—which tends to make the ball enter the roll phase later (further down the lane).[31] Conversely, a lower RG indicates the ball's mass is distributed more towards its center—making it "center heavy"—which tends to make it enter the roll phase sooner.[31]
Differential of RG is the difference between maximum and minimum RGs measured with respect to different axes.[31] Differential indicates the ball's track flare potential, and contributes to how sharply a ball can hook.[31] A higher differential indicates greater track flare potential—more angular motion from the break point to the pocket—and a lower differential indicates lower flare potential and a smoother arc to the hook.[31]
The lesser-used intermediate differential rating (sometimes termed mass bias rating) quantifies the degree to which a bowling ball core is symmetrical or asymmetrical.[31] Analytically, ID is defined by the USBC as the "difference in radius of gyration between the Y (high RG) and Z (intermediate RG) axes".[38] In practice, a higher ID indicates greater asymmetry, which causes more area to be created at the break point to cause the ball to respond more quickly to friction than symmetrical balls.[31]
Informally, a low-differential ball has been likened to one whose core is a spherical object (whose height and width are the same); a high-differential ball has been likened to a tall drinking glass (whose height and width are different); and a high-mass-bias ball has been likened to a tall drinking mug with a handle on the side (which has different widths in different directions).[37]
Higher-friction surfaces (lower grit numbers) cause balls to hook earlier, and lower-friction surfaces (higher grit numbers) cause balls to skid longer before reacting (hooking).[41]
Reactive cover stocks finishes include matte (aggressive reaction), shiny (longer skid distance than matte finish), pearl (greatest skid distance among reactive cover stocks), and hybrid (combination of skid distance and back end reaction).[41]
Effect of lane characteristics on ball motion
[edit]The phenomenon of lane transition occurs when balls remove oil from the lane as they pass, and deposit some of that oil on originally dry parts of the lane.[42][46] The process of oil removal, commonly called breakdown, forms dry paths that subsequently cause balls to experience increased friction and to hook sooner.[42][46] Conversely, the process of oil deposition, commonly called carry down, occurs when balls form oil tracks in formerly dry areas, tracks that subsequently cause balls to experience less friction and delayed hook.[42][46] Balls tend to "roll out" (hook sooner but hook less) in response to breakdown, and, conversely, tend to skid longer (and hook later) in response to carry down—both resulting in light hits.[43] Breakdown is influenced by the oil absorption characteristics and rev rates of the balls that were previously rolled,[42] and carry down is mitigated by modern balls having substantial track flare.[43]
Lane materials with softer surfaces such as wood engage the ball with more friction and thus provide more hook potential, while harder surfaces like synthetic compositions provide less friction and thus provide less hook potential.[42]
Higher-viscosity lane oils (those with thicker consistency) engage balls with more friction and thus cause slower speeds and shorter length but provide more hook potential and reduced lane transition; conversely, lane oils of lower viscosity (thinner consistency) are more slippery and thus support greater speeds and length but offer less hook potential and allow faster lane transition.[42] Various factors influence an oil's native viscosity, including temperature (with higher temperatures causing the oil to be thinner) and humidity (variations of which can cause crowning and cupping of the lane surface).[42] Also, high humidity increases friction that reduces skid distance so the ball tends to hook sooner.[44]
The lanes' physical topography—hills and valleys that diverge from an ideal planar surface—can substantially and unpredictably affect ball motion, even if the lane is within permissible tolerances.[42]
Manufacturers
[edit]The USBC maintains a list,[47] said to be updated weekly, of about 100 bowling ball manufacturers and their approved bowling balls.
Duckpin balls
[edit]Duckpin bowling balls are regulated to be from 4.75–5.00 inches (12.1–12.7 cm) in diameter and to weigh between 3 pounds 6 ounces (1.5 kg) and 3 pounds 12 ounces (1.7 kg).[48] They lack finger holes.[48] Though duckpin balls are slightly larger than candlepin balls, they have less than 60% the diameter of ten-pin balls, to match the smaller size of duckpins.[48] Duckpin balls are sometimes used for scaled-down ten-pin bowling lanes installed in arcades and other amusement facilities.[citation needed]
Five-pin balls
[edit]The basic specifications of five-pin balls are the same a duckpin balls: diameters from 4.75 to 5.0 in (12.1 to 12.7 cm), weights from 3 pounds 6 ounces (1.5 kg) to 3 pounds 12 ounces (1.7 kg); the balls have no finger holes.[49]
Candlepin balls
[edit]Candlepin bowling balls have a weight of between 2 lb 4 oz (1.0 kg) and 2 lb 7 oz (1.1 kg), and a diameter of 4.5 in (11 cm)—much smaller than the 8.5 in (22 cm) balls in ten-pin bowling, and even smaller than the 5.0 in (13 cm) balls in duckpin bowling .[50][51] Candlepin balls deflect significantly upon impact, being even lighter than the 2 lb 8 oz (1.1 kg) candlepins themselves.[50]
Nine-pin balls
[edit]American nine-pin bowling uses the same ball (and pins) as in ten-pin bowling.[citation needed] European nine-pin bowling balls (such as those used in German kegel) are smaller, sized between ten-pin and duckpin balls, and have no holes.[citation needed] The ball is 16 cm (6.3 in) in diameter and weighs approximately 2.85 kg (6.3 lb).[citation needed] There are also special balls for novice players, which is 14 cm (5.5 in) in diameter and weigh 1.9 kg (4.2 lb), often with two finger holes.[citation needed]
See also
[edit]Publications
[edit]- Benner, Donald; Mours, Nicole; Ridenour, Paul; USBC, Equipment Specifications and Certifications Division (2009). "Pin Carry Study: Bowl Expo 2009" (Slide show presentation). bowl.com (United States Bowling Congress, USBC). Archived (PDF) from the original on December 7, 2010.
- Freeman, James; Hatfield, Ron (July 15, 2018). Bowling Beyond the Basics: What's Really Happening on the Lanes, and What You Can Do about It. BowlSmart. ISBN 978-1 73 241000 8.
- Stremmel, Neil; Ridenour, Paul; Stervenz, Scott (2008). "Identifying the Critical Factors That Contribute to Bowling Ball Motion on a Bowling Lane" (PDF). United States Bowling Congress. Archived (PDF) from the original on June 3, 2012. Study began in 2005. Publication date is estimated based on article content.
- United States Bowling Congress (USBC) (February 2012). "USBC Equipment Specifications and Certifications Manual" (PDF). bowl.com. Archived (PDF) from the original on December 29, 2018.
- United States Bowling Congress (USBC) (February 2018). "Bowling Technology Study: An Examination and Discussion on Technology's Impact in the Sport of Bowling" (PDF). bowl.com. Archived (PDF) from the original on December 31, 2018.
- United States Bowling Congress (USBC) (2021). "Playing Rules 2021-2022" (PDF). bowl.com. Archived (PDF) from the original on November 2, 2021.
References
[edit]- ^ "Bowling" (PDF). Spalding's Athletic Library. Vol. 1, no. 3. New York: American Sports Publishing Company. December 1892. Archived from the original (PDF) on March 27, 2020.
- ^ a b c d e f g h i Carrubba, Rich (June 2012). "Bowling Ball Evolution". BowlingBall.com (Bowlversity educational section). Archived from the original on September 17, 2018.
- ^ Wiseman, Lucas; United States Bowling Congress (USBC) (May 7, 2014). "USBC Modifies Rule on Bowling Ball Gripping holes". bowl.com (United States Bowling Congress, USBC). Archived from the original on July 7, 2017.
- ^ "USBC Equipment Specifications and Certifications Manual" (PDF). bowl.com (United States Bowling Congress, USBC). February 2012. Archived (PDF) from the original on December 29, 2018.
- ^ Bigham, Terry (April 24, 2018). "Bowling Technology Study Conclusion / Research Summary and Specification Updates". Bowl.com. United States Bowling Congress (USBC). Archived from the original on May 26, 2019.
- ^ Barnes, Clifton (March 19, 2020). "2020 USBC Rule Changes On Bowling Ball Weight Holes By MDM Bowling Coaching". bowlersmart.com. Archived from the original on November 13, 2020.
- ^ a b c d Siefers, Nick (USBC research engineer) (April 23, 2007). "Understanding the relationship between core and cover stock". BowlingDigital.com (Courtesy of USBC Equipment Specification and Certification). Archived from the original on September 20, 2018.
- ^ Martin, Jimmy (May 12, 2011). "The Evolution of Bowling Balls". BowlingBall.com (Bowlversity educational section). Archived from the original on September 26, 2022.
- ^ a b c d e f "Bowling Balls: An In-Depth Overview". Bowling This Month. March 31, 2017. Archived from the original on April 12, 2019.
- ^ Barry, Dan (April 21, 2000). "Perfection Made Easy; Bowling a 300 Game Just Isn't the Feat It Used to Be". The New York Times. Archived from the original on June 7, 2016.
- ^ Carrubba, Rich (January 1, 2013). "Reactive Bowling Balls". BowlingBall.com (Bowlversity educational section). Archived from the original on August 6, 2020.
- ^ a b c "How Should My Bowling Ball Be Drilled?". BowlingBall.com (Bowlversity educational section). January 2015. Archived from the original on July 11, 2015.
- ^ a b c Carrubba, Rich (November 2012). "Your Bowling Ball Positive Axis Point". BowlingBall.com (Bowlversity educational section). Archived from the original on July 9, 2017.
- ^ a b Hickland, Ronald (April 11, 2017). "What is the difference between Pin up and Pin down Drilling on a Bowling Ball?". CTDbowling.com News section. (Web page archiving attempts failed.)
- ^ a b c d e Freeman & Hatfield 2018, Chapter 9 ("Track Flare, or Much Ado About Nothing?").
- ^ a b Freeman & Hatfield 2018, Chapter 5 ("You Say You Want a Revolution").
- ^ a b "Finger Inserts For New Bowlers". BowlingBall.com (Bowlversity educational section). 2013. Archived from the original on January 16, 2019.
- ^ Carrubba, Rich (October 2, 2011). "Understanding Bowling Ball Motion". BowlingBall.com (Bowlversity educational section). Archived from the original on May 5, 2023.
- ^ "What Are The Boiled Down Factors Affecting Bowling Ball Motion?". BowlingBall.com (Bowlversity educational section). April 13, 2015. Archived from the original on August 18, 2015.
- ^ a b Carrubba, Rich (February 5, 2013). "The Simple Keys Of Bowling Ball Motion". BowlingBall.com (Bowlversity educational section). Archived from the original on July 23, 2021.
- ^ a b "Your Bowling Ball Motion". BowlingBall.com (Bowlversity educational section). December 29, 2016. Archived from the original on February 9, 2017.
- ^ a b "Variables You Encounter When Bowling". BowlingBall.com (Bowlversity educational section). April 18, 2016. Archived from the original on October 12, 2016.
- ^ a b Stremmel, Ridenour & Stervenz 2008, p. 3.
- ^ "Bowling Ball Reaction Keys". BowlingBall.com (Bowlversity educational section). July 28, 2016. Archived from the original on November 10, 2016.
- ^ a b c d e f g h i j k Freeman & Hatfield 2018, Chapter 8 ("Why Does My Ball Hook?").
- ^ a b c d • O'Keefe, Bryan (2015). "Bowling Release Ratio". usbcbowlingacademy.com. Archived from the original on April 2, 2016. (date is approximate)
• "Adjusting Entry Angle". bowl.com (United States Bowling Congress, USBC). 2015. Archived from the original on April 17, 2017. (date is approximate) - ^ a b c d e f g h i Freeman & Hatfield 2018, Chapter 13 ("Create a Bowler's Tool Kit").
- ^ Rose, Tyrel (2019). "Improving Your Release / Tools, techniques, and practice drills for developing a more effective release". Bowling This Month. Archived from the original on April 5, 2019.
- ^ "Being Able To Adjust Your Axis Rotation Is A Tool Worth Having". BowlingBall.com (Bowlversity educational section). December 22, 2011. Archived from the original on March 5, 2021.
- ^ a b c Stremmel, Ridenour & Stervenz 2008.
- ^ a b c d e f g h i "Bowling Ball RG And Differential Range Ratings". BowlingBall.com (Bowlversity educational section). 2014. Archived from the original on December 26, 2014. Retrieved 25 September 2018.
- ^ "Picking a New Bowling Ball for the Average Bowler". National Bowling Academy. May 13, 2024. Archived from the original on July 19, 2024.
- ^ McEwan, Jason (August 2022). "A Guide to Bowling Ball Cores, RG, Differential, and Coverstock". National Bowling Academy. Archived from the original on 25 August 2022.
- ^ McEwen, Jason (2022). "A Guide to Bowling Ball Cores, RG, Differential, and Coverstock". National Bowling Academy. Archived from the original on March 21, 2023.
- ^ Stremmel, Ridenour & Stervenz 2008, p. 8.
- ^ Carrubba, Rich (September 7, 2010). "How To Find A Skid-Flip Bowling Ball". BowlingBall.com (Bowlversity educational section). Archived from the original on February 26, 2021.
- ^ a b "Ball Dynamics and Hook Potential". BowlingBall.com (Bowlversity educational section). 2005. Archived from the original on November 24, 2005. Retrieved 25 September 2018.
- ^ a b "Technical Terms" (PDF). bowl.com. United States Bowling Congress. Archived (PDF) from the original on September 20, 2018. Retrieved 25 September 2018.
- ^ Carrubba, Rich (February 4, 2013). "Bowling Ball Surface Grit Pads". BowlingBall.com (Bowlversity educational section). Archived from the original on November 11, 2020.
- ^ Carrubba, Rich (2012). "BowlVersity Q & A Part 2 / Q. Which are the most effective ranges of grit pads to use when altering bowling ball surfaces?". BowlingBall.com (Bowlversity educational section). Archived from the original on September 18, 2015.
- ^ a b "Understand Your Bowling Ball Reaction". BowlingBall.com (Bowlversity educational section). May 22, 2016. Archived from the original on December 2, 2018.
- ^ a b c d e f g h i Freeman & Hatfield 2018, Chapter 14 ("Applying Your Tools").
- ^ a b c Freeman & Hatfield 2018, Chapter 16 ("Advanced Considerations").
- ^ a b "Bowling Lane Adjusting From Pair To Pair". BowlingBall.com (Bowlversity educational section). June 28, 2016. Archived from the original on October 31, 2016.
- ^ "Bowling Catalog E". Gutenberg.org. Narragansett Machine Company. 1895. Archived from the original on July 1, 2018. Project Gutenberg release date: June 16, 2018.
- ^ a b c "Changing Lane Oil Conditions". BowlingBall.com (Bowlversity educational section). 2015. Archived from the original on September 18, 2015.
- ^ "Approved Ball List". bowl.com (United States Bowling Congress, USBC). Archived from the original on November 6, 2018.
- ^ a b c "Duckpin Bowling". paramountindustriesinc.com. 2017. Archived from the original on April 11, 2017.
- ^ "Accessories and Equipment / Accessoires et équipements (2015-2016 Season)" (PDF). PhippsBowling.com. 2016. Archived (PDF) from the original on March 28, 2017.
- ^ a b New Hampshire Candlepin Bowling Association (2013). "Candlepin Bowling Rules / Pin specifications and ~ / Ball specifications". Archived from the original on January 26, 2016. 2013 date estimated based on earliest archive date.
- ^ "Basics of candlepin vs. tenpin bowling". The Boston Globe. May 4, 2014. Archived from the original on May 13, 2014.
External links
[edit]- "Bowling Balls: An In-Depth Overview". Bowling This Month. March 31, 2017. Archived from the original on April 12, 2019.
- Carruba, Rich (2011). "How Bowling Balls Are Made". BowlingBall.com (Bowlversity educational section). Archived from the original on 24 March 2023.
- Carrubba, Rich (June 2012). "Bowling Ball Evolution". BowlingBall.com (Bowlversity educational section). Archived from the original on September 17, 2018.
- Horaczek, Stan (July 27, 2020). "The insides of pro bowling balls will make your head spin". Popular Science. Archived from the original on August 27, 2021.
- Muller, Derek and Zhang, Emily (September 25, 2021). "The Fascinating Physics of Bowling", Veritasium.