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BGonline.org Forums
Swiss format strategy
Posted By: Daniel Murphy In Response To: Swiss format strategy (Fabrice Liardet)
Date: Friday, 18 September 2009, at 11:34 a.m.
I played uncountable swiss format chess tournaments and I can swear that everybody plays the same number of rounds.
The modified Swiss in some American tournaments eliminates some players after losing, say, four matches.
Is there any strategy other than just win?
No, that's it. As Tom pointed out, every round is equally important. Matt mentioned a "Swiss gambit" -- as wiki puts it, " a risky strategy for facing weaker competition in the later rounds of a Swiss system [chess] tournament, by deliberately underperforming in the early rounds." In a backgammon Swiss, forget it! Losing an early round is certainly no advantage.
Now, in an unranked backgammon Swiss, that after two rounds the 0-2's will on average be worse players than the 2-0's, is a bet I'd take. But how much worse? Suppose you rate to finish 4-2 -- 67% -- against the field in a six round Swiss. If you lose the first round, you need to win 80% of your remaining matches to finish at your personal par. At a backgammon tournament, you may not even rate to win 80% of your matches against the 5 weakest players in the field. Plug in other numbers; it's hard to imagine how losing (on purpose?!) in a backgammon modified Swiss could be to your advantage.
Odd numbers of players are death to any Swiss tournament under time pressure since someone is always sitting out without a match
I don't understand this. If the field size is odd, give one player a bye and a point each round, that's all. Give it to the player with the worst record who has not yet had a bye. That may be unfortunate for the player who must sit out, but has no impact on the rest of the field. Late round byes have no impact at all on competition for top prizes. Early round byes would have little impact, either, if backgammon pairings were done by rating, but that's not an idea I've heard anyone endorse.
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I must say, a modified Swiss tournament is not hard to run, and can be run on schedule. What you need is a reasonable schedule and a focus by director and players on completing matches on time, reporting results immediately, pairing new rounds efficiently, and starting each day and every round on schedule.
Here's the format of the Danish Doubles Championship and of the Danish Mixed Doubles Championship, the last of which I directed for several years:
Two days, Saturday and Sunday.
11 rounds. All players play 11 rounds.
9 point matches.
6 rounds Saturday, 5 rounds Sunday.
Modified Swiss:
(a) Initial pairings are not by rating. Players are ranked randomly solely for the purpose of making pairings in each. After each round, players are reordered first by record and then by rank. For example, in round 1 player #1 plays #2, #3 plays #4, #5 plays #6, #7; if #1, #4 and #6 and #7 won, then (in an 8 player tournament) round 2 pairings would be 1 vs 4, 6 vs 7, 2 vs 3 and 5 vs 8. Subsequent pairings are made in the same way, except that no two players ever play each other more than once.
Since I did the draw manually, each player had a numbered card on which opponents, results and cumulative points were recorded. With our field sizes, it was easy enough to record data as matches were completed, reorder the stack of cards at the end of a round and go through the stack from top to bottom to make the pairings for the next round. But if we'd had closer to 64, I would certainly have used a computer for pairings.
(b) Pairings for each subsequent round are like vs. like record, e.g., in Round 3, the 2-0's play each other, the 1-1's play each other and the 0-2's play each other.
(c) If there's an odd number of players, the lowest ranked player with the worse record gets a bye, but no player gets more than one bye.
(d) If a match is not completed before the next round must start, both players temporarily receive 0.5 points for the incomplete match and are inserted in the ranking for pairing purposes according to their temporary cumlative score. For example, after three rounds, you'll have players at 3-0, 2-1, 1-2 and 0-3, and perhaps two or four (at most!) say, at 1.5-1.5 or 2.5-0.5. No big deal. The records are adjusted later whenever the match is completed, e.g., during a scheduled break or at the end of day one.
(d) At the end, record determines standing, and if necessary trophy standing is determined according to a system of corrections based on opponent record. For example, if 2 players end at 9-2, and 3 players end at 8-3, then the 9-2's split first/second place prize money and the 8-3's split third/fourth/fifth, and corrections determine trophy standing.
Scheduling: in the tournament I directed, I scheduled 90 minutes per round including time for a draw between rounds. That was (intentionally) overly optimistic for most rounds, but 105 minutes was surely enough. Some matches were over in an hour, almost all in 90 minutes, and only the rare match was incomplete after 1 3/4 hours. Players need to report results immediately and director needs to keep on top of matches in progress, to start organizing and data entering for the next pairings as results come in. No need to wait on that until all matches are over.
Eleven rounds of nine point matches in two days was a lot! The days were long, and nobody had a Sunday night flight to catch. But we ran tournaments on time (at 105/round), pairing between each round, with a manual draw system and no clocks; surely today with clocks and, perhaps, with a computerized draw, it must be possible to run a nine (or fewer!) round Swiss in two days on schedule ending each day at a reasonable time. Somewhere, I've seen talk of allowing as much as 2.5 hours for a round of 9 point matches. That's simply too much time.
With a reasonable schedule and time available, I don't see a need for multi-round draws or extra problems (if any -- see Rich's comment) created by dividing the field into smaller groups -- Sam's description of the procedure for intermediate division in Chicago sounds fine and painless for the directors, but I wouldn't want to see 4 or 5 rounds pre-paired in an open flight (not in a Swiss; there's a term for a tournament with 5 pre-paired rounds: "32-player cup format").
I know there are commercially available pairing systems designed for chess tournaments but I'm not up on prices and suitability to whatever modified version a backgammon tourney uses. In Denmark I had available to me an old DOS program for pairings; if I remember correctly, we actually planned to use it the one year but had some computer or printer problems and ended up doing it manually, which went smoothly enough, so we stuck with that. But anyone contemplating running a modified Swiss tournament might want to contact the DBgF secretary, and find out what if any program is being used at their two Doubles Championship tournaments these days.
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