I’m practicing pairing. After doing the practice setup sent out with the Club TD stuff, I generated my own test data: A 1950, B 1925, C 1891, D 1860, E 1790, F 1777, G 1760, H 1758, I 1714, J U1700, K U1600. The U’s are unrated, but playing strength is as given for determining results: higher rated wins, but draw if within 50 points.
After 2 rounds, the top score group has 3 players (ABC), and the next score group has 5 players (DEFHI). 29D1 states that odd players are always demoted, which would give groups of 2 and 6.
Since this ends up pairing A and B in round 3 of a 4 round swiss, I want to make sure that promoting the top player in the 2nd score group (evening out score groups at 4 and 4) is not a possibility. Colors work out OK in either case.
Given the facts as stated, A should play B, C should play one of the players in the next group (presumably D), and the remaining players in the second group should be paired among themselves.
Note that even if you “brought up” the top man from the second group, it would produce the same pairing. The odd man is not paired as part of the next score group; he is paired against the highest eligible player in that group.
For those with long memories. note also that “bringing up” player D would bge equivalent to “dropping the middle man” – instead of AB and CD, you would end up with AC and BD. This is an old method, going back to the Harkness “Blue Book,” which still has partisans in some areas of the country. It is, however, no longer standard, and you would have had to announce it in advance.
If by “demoted” you mean treating the player as though he were a member of the lower score group, then you are seriously mis-interpreting 29D1.
You should NEITHER place the “demoted” player in the second group according to his rating NOR treat him as the top member of the second group. Rather, you should simply pair the bottom player in the first group AGAINST the top player in the second group. This pairing is an “extra” pairing – it should not be regarded as one of the first-group pairings, nor as one of the second-group pairings, either.
In your example, with groups of 3 and 5, instead of converting to 2 and 6 by “demoting” or to 4 and 4 by “promoting”, you should think of it as 2, 2, and 4 – the first group, the extra pairing, and the second group.
The rulebook never uses the word “demoting” or “promoting”, and by thinking of it that way you are confusing yourself.
I should mention that, when players in different score groups are paired, transpositions are allowed for the usual reasons, e.g. to improve colors. In an 11-player group, for example, instead of dropping player 11, you could drop player 10 (or 9, or 8, etc) as long as the switch is within 200 points (to equalize colors) or 80 points (to alternate colors). Or, for that matter, from the second group, instead of bringing up player 1, you could bring up player 2 (or 3, etc), again being mindful of the 200- and 80-point rules.
By the way, I personally would find it useful to have more “homework” like this, with answers and explanations, made available somewhere. Anyone know of a source? Even if I could use one of the pairing programs (I mainly use a Un*x box, so WinTD and SwissSys would be problematic), I would like to see explanations like this.
There was someone working on a *nix based pairing program a while back, I don’t know if he gave up on that or not. It took YEARS for WinTD and SwisSys to get to the point that they are at today.
There are a few available for un*x, in various stages of readiness. All the ones that are usable today (that I’m aware of) are written by folks in Europe. I’d want to hear from an experienced USCF TD who’s used them (vegachess.com, for example), before I would want to use it for a tournament.
Besides, I need to do this by hand initially to understand the rules. No pain, no gain, and all that.
Swiss Sys will run a W95 platform. Since a used W95 system is much less expensive than the cost of the software itself, why not just get one and use it? (I bought a forklift full of W95 systems for $7 each, not much more than the shipping cost on buying the SW)
Also, many flavors of Unix will have SW that will emulate windows fairly well – you might find one that will work with Swiss Sys.
Bravo! I wish more TDs would adopt this attitude. I fear we may be raising a generation of TDs who know nothing about pairings, and couldn’t pair by hand to save their necks.
Even some extremely experienced TDs will just let the computer do the pairings, then rip them out of the printer and post them without even looking. This can lead to some embarrassing situations. A couple of years ago in a significant Illinois event, a couple of players objected to the pairings, so the TDs changed them AFTER they were posted. And the pairings the TDs made were, in my opinion, inferior to those the software had made.
After reading through all this part of the rulebook again, I believe that it was the wording in the initial paragraph of 29D that might have led me astray:
“At least one player, and possibly more, will have to be dropped to play in a lower score group.”
After reading the subsections, it eventually becomes clear that the player does not actually become part of the lower score group, but I personally think that the way you stated it in your initial reply makes it much more clear (basically, an intermediary score group is formed). Phrases like “dropping down to another score group” seem to be used a few other times in 29D as well.
I agree the wording could be improved. And so could my objection (in my previous post) to the word “demoting”. Maybe I should have said that a demotion AND a promotion are involved. In other words, the questions of who to drop and who to bring up should BOTH be pondered.
Here’s another example:
Top score group: 11 players (5 due white, 6 due black)
Second score group: 15 players (8 due white, 7 due black)
In this example, there is something to be said for pairing a due-black in the top group against a due-white in the second group, thus (with any luck) creating perfect colors in BOTH groups. This could easily involve dropping a player other than the lowest AND bringing up a player other than the highest, i.e. transposing both of the (originally contemplated) odd players.
Vega is pretty good, can do USCF reports for upload, and the Linux version is free (the Windows version is still pretty cheap). I have been using it for our club’s monthly tournaments for almost a year now. Give it a try. Feel free to message me if you have questions.