Author: Vincent Diepeveen
Date: 09:15:58 06/11/04
Go up one level in this thread
On June 10, 2004 at 08:04:55, José de Jesús García Ruvalcaba wrote: >On June 09, 2004 at 17:29:39, Dieter Buerssner wrote: > >>On June 09, 2004 at 13:24:54, José de Jesús García Ruvalcaba wrote: >> >>>On June 09, 2004 at 08:31:21, Peter Berger wrote: >>> >>>> >>>>I enjoyed reading your posts but you generalized the problem too much IMHO. I >>>>specifically referred to legal Swiss pairings only. I agree that there will >>>>always be some way of pairing left but not one that also follows the much >>>>stricter rules for Swiss pairings. >>>> >>>>If you have sufficient time you can look them up here: >>>>http://www.fide.com/official/handbook.asp?level=C04 >>>> >>>>Peter >>> >>>Well, I did not generalise the problem too much. The FIDE swiss system rules are >>>for sure strict, but they allow score brackets to be melted together if there is >>>no other way of producing a pairing. Doing that succesvely until we get only one >>>bracket (with n-3 rounds for n players that could easily happen according to the >>>rules), we are in the situation I described. >>> >>>See >>>http://www.fide.com/official/handbook.asp?level=C0401B >>>B.3 is a relative pairing criterium. >>> >>>in C.13 of >>>http://www.fide.com/official/handbook.asp?level=C0401C >>>it is shown under which circumstances the last two score brackets are joined. >> >>The above two are for "Swiss tournament based on rating". The first of 3 Swiss >>systems shown in the FIDE handbook. I had the impression, that typical Swiss >>systems are played with the 2nd system shown (for example in Paderborn). But I >>am not sure. > >Sorry, I did not make any reference to swiss system based on rating >(participants at the WCCC do not have a reliable rating anyway). For those >interested, the swiss system based on rating is described at >http://www.fide.com/official/handbook.asp?level=C0403 >but my previous links come from other sections. At the world champs pairing happens at Buchholz not at seeding (perhaps first 2 or 3 rounds pairing happens on seeding, it is up to the tournament director to decide that). So from round 4 and further any possible scenario must take into account that favourites keep winning and have more buchholz in general than weaker participants. You can simply not assume a competition where everyone draws each other. No pairing system will work to show who is the best when every round everyone draws. >> >>>And in 9.6 of >>>http://www.fide.com/official/handbook.asp?level=C0402B >> >>Which is here >> >>>it is described how and in which direction the median score group is extended. >> >>I don't follow here. Can you explain it more carefully to me? > >To make a pairing, the absolute pairing rules must be always followed. As you >point out a few lines down, one of them is never pair the same two players more >than once. In order to achieve that anything is allowed, and the last resource >(when nothing else works) is simply to melt two score brackets together. >If you are making the pairings of the median group (the group that has m/2 >points after m rounds) at the end, and are forced to melt it together with >another one, it can be done in two directions: above and below, and the rules >tell you exactly in which direction it has to be done. > >>In the above >>example, there was no problem to pair round 3 with this system. > >Six players, n=6, there should be no problem to pair round 3=n-3, but it might >not be posible to pair round 4=n-2 > >>I do not see any >>rules, that look ahead to the next round. > >There are no rules that look ahead to the next round. > >>When you pair the 4th round, there is >>no possible pairing, whatever you try. There probably most important rule, never >>pair the same two players again, cannot be fullfilled. >> >>Regards, >>Dieter > >The nightmare scenario from Peter is 11 rounds, and 13 or 14 players (d.h. n=14 >and n-3=11 rounds). I for myself do not worry and am only happy that I am not >the tournament director. >José.
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