Double elimination

Double elimination refers to a tournament format in which a team is not eliminated until it has lost two games. This is in contrast to the direct elimination format used in most sports, in which the eventual winner is the only competitor who has won all of its matches. The format is often used in baseball because of the random nature of many wins, in which a single strong pitching performance can lead to an upset; in a double elimination format, a team can bounce back from one poor performance to eventually win a tournament. Another advantage is that such a tournament can be set up for any number of teams without having to resort to byes or seeding to offset a number of teams that is not a power of 2.

One typical outcome of the double elimination format is that the championship usually pits an undefeated team against one who has already lost one game; as a consequence, the former team needs only to win one game to claim the title, while the latter must win two. To offset that imbalance, many tournaments drop the double elimination requirement for the final game, and/or for semi-final or quarter-final rounds.

The format has been used in the College World Series, the CCCAA championship, the National Baseball Congress World Series and many other amateur tournaments. It is rarer in professional play, but the format has been in effect for some of the rounds of the various editions of the World Baseball Classic.