Am I just unfortunate?

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Roger de Coverly
Posts: 21301
Joined: Tue Apr 15, 2008 2:51 pm

Re: Am I just unfortunate?

Post by Roger de Coverly » Sun Jan 25, 2015 9:34 pm

Alistair Campbell wrote: Wouldn’t things be relatively symmetrical? So being bottom seed would also be a good predictor?

You are going to have to explain this last point to me…

Swiss pairing systems attempt to follow colour alternation and alternate by board. So assuming results go more or less by seeding, you are going to get an equalish number of players who had white the round before, looking for black and vice versa. They are also going to be respectively the odd players or the even players.

Assume 16 players, then round 1 is

1v9
10v2
3v11
12v4
5v13
14v6
7v15
16v8

If all the higher seeded players win, you have 2, 4, 6 and 8 all looking for white and 1, 3, 5, 7 looking for black. With colour alternation high on the list of attributes, you are likely to get odd v even again.


I'd suspect that being the lowest seed, the bottom markers may well be the ones least likely to retain colour sequence, as they will always be the ones to retain the same colour.

There was an incident in one of the five round events at the British a few years ago. Two players had started with two Blacks and lost them both and they had been the only two players to lose both. Do you pair them in the third round or float them?

Michael Flatt
Posts: 1235
Joined: Tue Jul 02, 2013 7:36 am
Location: Hertfordshire

Re: Am I just unfortunate?

Post by Michael Flatt » Sun Jan 25, 2015 11:35 pm

Swiss Pairing Rules can be downloaded from the Chess Arbiters' Association website: http://www.chessarbitersassociation.co. ... loads.html

Even if the tournament had an even number of rounds there is no guarantee that all players would get an equal number of blacks and whites.

In a tournament with an odd number of rounds taking a half point bye in an early round will improve your chance of, but not guarantee, an equal distribution of colours. (In relation to pairing, byes are colourless.)The penalty, of course, is not playing one game and giving up half a point.

Can anyone say whether the introduction of computer pairings has made any noticable difference in the number of players having a run of tournaments with a disproportionate number of games as black?