UFC 21 marked significant rule changes due to the Council of the Mixed Martial Arts Commission: preliminary bouts now consisted of two five minute-rounds, main card bouts were three five-minute rounds and championship bouts were five five-minute rounds (similar to the Unified Rules of Combat used today in the USA). UFC 21 was the first UFC event to adopt the 10-point must system, commonly used in boxing, to judge fights instead of each judge merely stating their choice of fighter. 10 points are awarded for fighters who win the round, 6-9 points for the fighter that loses the round. Points awarded for Octagon control, effective striking, grappling/near submissions, and aggressiveness.