From: "Daniel M. Toebbens" HMI DE> Date: 14 may 2003 Subject: Re: MacMahon & SOS [was: Shogi Tournament in Pullach - Munich] On Tue, 13 May 2003, J Andrew Lipscomb wrote: > Le Mardi, 13 mai 2003, à 05:39 America/Montreal, Daniel M. Toebbens a > écrit : > > > From the score table below it seems to me that the use of SOS as tie > > breaker does not go well together with strong MacMahon. > > If I may risk asking a stupid question, what exactly is "strong" > MacMahon--and is there such a thing as "weak" MacMahon? In the MacMahon system you divide all players in the tournament into classes according to their strength; the higher the class, the more points it gets in advance. But you can vary the total number of classes you use in a tournament: With zero classes you'd get the original Swiss system. On the other end of the scale you can use one class for each grade (or its equivalent in elo points). As far as I know this is common in Go and is also the original idea of the MacMahon system. That does mean of course, that in a tournament you cannot move to far away from your starting position. I.e. a 10 kyu would have to win 6 rounds to get the same number of points as a 4 kyu who has lost all 6 rounds. But then again, a 10 kyu should not be able to win against a 4 kyu. In German shogi tournaments often a variant with very few MacMahon classes is used. I.e. the last German Open Championship used three classes with 15-7 kyu getting zero points in advance, 6-1 kyu getting one point and dan players getting two points. That would be 'weak' MacMahon as opposed to 'strong' MacMahon or 'gentle' MacMahon as opposed to 'step' MacMahon or 'soft' MacMahon as opposed to 'hard' MacMahon or .... Actually I don't know if any of these terms is offical, but similar combinations are used in various other fields. Daniel Toebbens