singleelimination

Single-elimination, also known as the knockout format, is a tournament structure in which a participant is eliminated after a single defeat. The competition progresses through a series of rounds in which winners advance and losers are removed, until only one competitor remains as the champion. When the number of entrants is not a power of two, byes or preliminary matches are used to fill a balanced bracket, often granting byes to top seeds.

Participants are paired according to a predefined bracket, and seeding is used to distribute strong competitors across the draw to reduce the likelihood of top seeds meeting early. Byes allow higher-ranked entrants to skip early rounds, preserving the balance of the bracket.

Advantages of single-elimination include simplicity, speed, and a clear, decisive outcome. It is easy to organize, explain, and televise, and it produces a single champion with a straightforward progression. Disadvantages include potential unfairness from seeding or bracket luck, the possibility that strong competitors meet before the final, and the lack of opportunities to recover from a single poor performance beyond one loss.

Variations may involve different seeding methods, the use of byes, or occasional reseeding after rounds. Common applications span sports tournaments, eSports, and card games. Notable examples include the knockout stages of tournaments such as the FIFA World Cup and the NCAA March Madness basketball tournament, both of which determine a champion through successive single-elimination rounds.