The Davis Cup is the premier international team event in men's tennis. The largest annual team competition in sport, the Davis Cup is run by the International Tennis Federation and is contested between teams of players from competing countries in a knock-out format. In 2005, 134 nations entered teams into the competition. All rubbers are normally best-of-5 sets with the 4 first sets being using tiebreak, if a 5th set is played its long (as example 8-6). If a team has clinched the rubber before all 5 matches are played, any remaining reverse singles matches are shortened to best-of-3 sets. In the lower divisions usually best-of-3 sets are played.