Chess

For other meanings, see Chess (disambiguation).

Chess (from the Persian word Shah) is a board game for two players played on a square board divided into eight rows (or ranks) and eight columns (or files) creating 64 individual squares which alternate in color orthogonally (traditionally as white and black although other colours are sometimes used). Each player begins the game with 16 pieces: eight pawns, two knights, two bishops, two rooks, one queen and one king with each kind of piece moving uniquely. The two players' pieces are differentiated by contrasting colors. The object of the game is to make it impossible for the opponent to prevent the capture of his or her king (checkmate). It is widely believed that the game is a modified version of the Indian game Chaturanga.

From left, a white king, black rook and queen, white pawn, black knight, and white bishop.

Introduction

Chess is not a game of chance; it is based solely on tactics and strategy, and for this reason, it is sometimes known by the sobriquet the "Game of Kings". Nevertheless, the game is so complex that not even the best players can consider all contingencies.

File:Chessset2.jpg

A translucent chess set arranged for visual effect. It's unlikely that a real chess match would unfold into such a perfectly symmetrical configuration.

The number of legal positions in chess is estimated to be between 10⁴³ and 10⁵⁰, and the game-tree complexity approximately 10¹²³. The game-tree complexity of chess was first calculated by Claude Shannon (father of information theory) as 10¹²⁰, a number now known as the "Shannon number". Typically an average position has thirty to forty possible moves, but there may be as few as zero (in the case of checkmate or stalemate) or as many as 218.

Chess is one of humanity's most popular games; it has been described not only as a game, but also as an art, science, and sport. Chess is sometimes seen as an abstract wargame; as a "mental martial art", and teaching chess has been advocated as a way to increase mental prowess. Chess is played both recreationally and competitively in clubs, tournaments, online, and by mail (correspondence chess). Many variants and relatives of chess are played throughout the world; amongst them, the most popular are Xiangqi (in China), Janggi (in Korea), Shogi (in Japan), and Buddhi Chal (in Nepal), all of which come from the same historical stem as chess.

History

Although many countries claim to have invented it, the preponderance of evidence is that chess originated from the Indian game Chaturanga, about 1400 years ago. There is a story that a king in India wanted to reward the poor mathematician who invented the game. The mathematician requested the king to gift him one grain of rice for the first square, two for the second, four for the third and so on, doubling the grains for each successive square. The king, considering this a trivial prize, agreed, and lost his entire granary even before the 40th square was reached. This story is often quoted as an example of a Geometric progression.

Later, chess spread westwards to Europe and eastwards as far as Korea, spawning variants as it went. From India it migrated to Persia, and spread throughout the Islamic world after the Muslim conquest of Persia, although many Islamic scholars consider Chess to be haraam (prohibited), whether or not it is played with the intention of gambling. Chess then reached Russia via Mongolia, where it was played at the beginning of the 7th century. It was introduced into Spain by the Moors in the 10th century, where a famous games manuscript covering chess, backgammon, and dice named the Libro de los juegos was written under the sponsorship of Alfonso X of Castile during the 13th century. Chess reached England in the 11th century, and evolved through various versions such as Courier. However, the origins of chess are still questioned as the oldest archaeological chess piece was found recently in the ancient city of Butrint in Albania.

A typical Staunton-design set and clock

By the end of the 15th century, the modern rules for the basic moves had been adopted from Italy: pawns gained the option of moving two squares on their first move and the en passant capture therewith (see pawn for explanation); bishops could move arbitrarily far along an open diagonal (previously being limited to a move of exactly two squares diagonally) while losing the ability to jump over the intervening square, and the queen was allowed to move arbitrarily far in any direction, making it the most powerful piece. (Before, she could only move one square diagonally.) There were still variations in rules for castling and the outcome in the case of stalemate.

These changes collectively helped make chess more open to analysis and thereby develop a more devoted following. The game in Europe since that time has been almost the same as is played today. The current rules were finalized in the early 19th century, except for the exact conditions for a draw.

The most popular piece design, the "Staunton" set, was created by Nathaniel Cook in 1849, endorsed by Howard Staunton, a leading player of the time, and officially adopted by Fédération Internationale des Échecs (FIDE) in 1924.

Chess's international governing body is FIDE, which has presided over the world championship matches for decades. See World Chess Championship for details and a more in-depth history. Most countries of the world have a national chess organization as well.

See also

• Origins of chess, Cox-Forbes theory, Chess in early literature, Early arabic chess literature, Chess in Europe, Chess tournament history, World Chess Championship, Famous entities with chess related names, World records in chess, Timeline of chess

Notation

Until the 1970s, at least in English-speaking countries, chess games were recorded and published using descriptive chess notation. This is still used by a dwindling number of mainly older players who emphasise its practical advantages such as being more mistake-proof. However, it has been largely supplanted by the more compact algebraic chess notation. Several notations have emerged, based upon algebraic chess notation, for recording chess games in a format suitable for computer processing. Of these, Portable Game Notation (PGN) is the most common. At the other extreme, a notation which sacrifices playthroughability for concision is Steno-Chess which minimises the number of characters required to store a game. Apart from recording games, there is also a notation Forsyth-Edwards Notation for recording specific positions. This is useful for adjourning a game to resume later or for conveying chess problem positions without a diagram.

Computer chess

Once the sole province of the human mind, chess is now played by both humans and machines. At first considered only a curiosity, the best chess playing computers like Shredder or Fritz have risen in ability to the point where they can seriously challenge and even defeat the best humans.

Garry Kasparov, then ranked number one in the world, played a six-game match against IBM's chess computer Deep Blue in February 1996. Deep Blue shocked the world by winning the first game in Deep Blue - Kasparov, 1996, Game 1, but Kasparov convincingly won the match by winning three games and drawing two. The six-game rematch in May 1997 was won by the machine which was subsequently retired by IBM. In October 2002, Vladimir Kramnik drew in an eight-game match with the computer program Deep Fritz. In 2003, Kasparov drew both a six-game match with the computer program Deep Junior in February, and a four-game match against X3D Fritz in November.

See also

• Deep Blue, Shredder, Deep Junior, Deep Fritz, GNU Chess, XBoard/Winboard, Chess symbols in Unicode

Subject overview

Rules of chess

• Official FIDE rules
• Equipment: Chessboard, Chess pieces, Game clock
• The Movement of the Pieces: Bishop, King, Knight, Pawn, Queen, Rook, Castling
• Tournament organization
• Administrative bodies:
  • FIDE
  • United States Chess Federation

Basic concepts

• Chess terminology
• Chess strategy and tactics
• Demonstration game
• Tactical elements: Fork, Pin, Skewer, Discovered attack, Zwischenzug, Undermining, Overloading, Interference
• Strategic elements: Chess opening
• Middle games: Hypermodernism
• Endgames

Famous chess games

• The immortal game between Adolf Anderssen and Lionel Kieseritzky (1851)
• The evergreen game between Adolf Anderssen and Jean Dufresne (1852)
• The opera game between Paul Morphy and two allies, the Duke of Brunswick and Count Isouard (1858)
• Lasker - Bauer, Amsterdam, 1889, the first example of the famous double bishop sacrifice
• The Game of the Century between Bobby Fischer and Donald Byrne (1956)
• Karpov - Kasparov, 1985, Game 16, considered by Kasparov to be his best game against the reigning champion (outside link)
• Deep Blue - Kasparov, 1996, Game 1, the first game where a chess-playing computer defeated a reigning world champion using normal time controls (1996)
• Kasparov versus The World, in which the reigning world champion played, via the Internet, against the entire rest of the world in consultation (1999)

Chess variants

A chess variant is any game derived from or related to chess.

The chess variants can be roughly categorized as follows:

• handicap variants, where one player starts with more pieces than the other
• shuffle chess, where non-standard starting positions are used (the best known version is Fischer Random Chess)
• fantasy variants (aka "Fairy chess" or "Heterodox Chess"), where new pieces are used or other radical rule changes are made
• national games, like Shogi (Japan), Xiangqi (China), Janggi (Korea) and Makruk (Thailand)

The categories may also be combined.

See also

• Game theory
• ELO rating system
• Chess and mathematics
• Chess as mental training
• Correspondence chess
• Chess problems and puzzles
• List of chess players
• Chess-related deaths
• Internet Chess Club
• Letsplaychess server
• List of chess topics

Chess literature

• Chess columns in newspapers
• Chess libraries
• Collections of Chess Games
• Opening Manuals

Chess in the arts and literature

• Through the Looking-Glass
• Searching For Bobby Fischer
• Danse Macabre
• The Luzhin Defence
• The Royal Game by Stefan Zweig.
• Chess and music
• The Lewis chessmen also inspired Noggin the Nog.

External links

• Official FIDE Website
• Quotes from Wikiquote
• 515 chess stories
• Compilation of chess variants and fairy pieces
• Free Internet Chess Server (FICS)
• WikiTeX chess supports editing chess games directly in Wiki articles.