Placement in go tournaments
Placement is based on Number of wins (Swiss tournaments) or on Mac-Mahon
score (Mac-Mahon tournaments). When tie-breaks are necessary, the most
frequent criteria are listed below:
SOS, SOSOS and SODOS
Very popular in Mac-Mahon tournaments
Opponent's score is corrected with the the handicap if any.
- SOS : Sum of Opponents Scores.
The Scores in question are usually Mac-Mahon scores
The score that is taken in account is the score at calculation time
(and not at game time)
- SOSOS : Sum of Opponents SOS
- SODOS : Sum of Defeated Opponents scores
Exploits Tentés, Exploits Réussis
The idea is to take in account the difficulty of the game. A game
is assumed to be difficult for a player if the actual handicap (AH) was,
for that player, more difficult than Natural Handicap (NH)
- if AH < NH, then coef = 0 (easy game)
- if AH = NH, then coef = 1 (normal game)
- if AH = NH +1 then coef = 2 ( difficult game)
- if AH >= NH +2 then coef = 3 (very difficult game)
ET is the sum of opponents scores, with coef as a weight factor
ER is the sum of defeated opponents scores, with coef as a weight factor
CUmulative Sum of Scores
CUSS after round 1 is the score of the player himself
CUSS after round 2 is the CUSS of round 1 plus the score of the player
himself after round 2
CUSS after round n is the CUSS of round n-1 plus the score of the player
himself after round n
The idea is that, in most pairing systems, it is a better performance to win the former games and lose the last one than to lose the first game and win the other ones.
An other positive argument in CUSS favour is that it does not depend on the opponents behaviour after the game.
If one player has won against all the other players with the same score
and lost against no one, then Dir = 1 for this player and Dir = 0 for
the other players.
If no player maches the above condition, then Dir = 0 for all the players
of the group