One of the references cited in that paper is this: http://emis.ams.org/journals/DM/v71/art3.pdf, which treats pairing a round of a Swiss as a stable roommates problem where the aim is to get a stable matching (no two players would rather play each other than the opponents they've got) while minimising both the maximum score difference and the maximum absolute colour preference. They don't do a very good job of it, but there are some numbers in there that could be fine-tuned to make it better.Roger de Coverly wrote: ↑Mon Apr 09, 2018 11:37 pmThat view was obsolete fifty years ago when Stewart Reuben and others devised any number of deterministic systems for making pairings based on the rankings of players.
I wonder what would happen if you also tried to minimise the deviations of the difference in ranking from the ideal value, which would be half the size of the score group. I might try that at some time that isn't 1:25am.
EDIT - I've knocked something up in Excel, and discovered a possible problem with treating pairing as a stable roommates problem: floats. If you had an odd number in the (1) score group of a Swiss, your downfloat would be forced to play someone from the (0.5) group, even if more stable pairings existed within the (0.5) group. A stable roommates solution would potentially lock in all the pairings of the (0.5) group and force the downfloat to play someone from the (0) group. More fiddling needed...