The round-robin tournament also called the all-play-all-tournament is a league tournament type that allows each participant to play every other participant an equal number of times. In a single round-robin schedule, each team plays every other team once. If each team plays each team twice it is called double round-robin. The term is rarely used if each team plays each other more than twice and is never used when each team does not play all other teams equally (as in the case of most professional sports)