- McMahon system tournament
-
A McMahon system tournament is a generalized case of the Swiss system tournament, used for games such as go and chess.
Like a Swiss tournament, all players compete in the same number of rounds against various other players. Unlike Swiss, the players do not all start with zero points, but are awarded initial points based on their rating prior to the tournament. The system features an "upper bar", set to a specific rating, so that all players that are considered to have a chance to win the tournament start with the same (maximum) number of points.
Players are paired each round against an opponent that has an equal or almost equal number of points so far, and gain a point for each round they win or half a point for a draw. The player with the highest number of points after the last round is the tournament winner, with various tie-breaking systems.
The system is named after Lee McMahon of Bell Labs, and was originally used as a club ranking system at the New York Go Club. It was then adopted for go tournaments in Britain, and has since become the most popular tournament system used in Go. Use of the McMahon system does not determine policy on other tournament questions such as whether to pair players from the same club, whether to use accelerated pairings, whether Go games should be even or handicap, etc.
The advantage of the McMahon system over the Swiss system is that it requires fewer rounds to find a winner, and that it avoids extreme match-ups (very strong players against very weak players) in the earlier rounds. By matching up possible tournament winners earlier, the system allows for more games amongst this group, and thus improves sampling.
External links
Categories:- Tournament systems
- Go (game)
- Go stubs
Wikimedia Foundation. 2010.
