Hi, I’m a TD in central Texas and I have a couple questions about pairings for a round robin. The rulebook doesn’t address these issues.
When a player drops out, how do you score the byes that his future opponents will receive? Will they get a full, half, or zero point? Is this effected by the withdrawn player’s record?
Another question: in a 7 player round robin (using the 8 player table) for instance, if a player drops out does this warrant any other changes. Having 2 different players with byes each round would seem odd.
I think you’re confusing yourself by thinking about a round robin as though it is a Swiss. The “bye” is a Swiss system construct to deal with having an odd number of players to pair. It is the Swiss system’s way of handling not being able to give every player an opponent. The player with the bye is given a full point for the round because giving the player anything less would unfairly penalize the player. (By not having an opponent, the player is deprived of the opportunity to win the game and to score a full point.)
This consideration simply does not apply to a round robin. The round robin has the built-in advantage that all players face exactly the same field. So, if there is an odd number of players in a round robin, there is no need whatsoever to compensate players for not having an opponent; every player in the round robin will have exactly one round without an opponent. Consequently, there is no reason to hand out “free points” to players. In fact, doing so is a mistake if tie breaks are used, since it skews the results of Sonneborn-Berger tiebreaks. (Please review rule 34E8.)
Now, according to rule 30B, if the withdrawn player has completed at least half the schedule (in other words, he has played at least three games in a seven player round robin), his results count toward the final score of the opponents he played. The opponents who did not play against the withdrawn player would receive a full point toward their final results, and (of course) the withdrawn player would receive zero points for the unplayed rounds. Again, please note that these points only count toward final standings and prize awards; these are not rated games.
If the withdrawn player did not complete at least half the schedule, you simply ignore his results (but see below for rating purposes). That is, if the player withdraws after either one or two rounds, you continue with the pairings as given in the 7-8 player table, but you only count the results of the six remaining players at the end for final standings and prize purposes.
Since that last paragraph might be unclear, let me give a more specific example. Let’s say player #7 withdraws after the third round. Players #1 through #6 complete the schedule. According to the round robin pairing tables for 7 or 8 players, player #7 would have been paired against player #1 in the first round and player #6 in the third round (and would have “sat out” round 2). In that case, at the end of the tournament, you consider the results of the games among players #1 through #6among themselves for the final results. You ignore the results of the games players #1 and #6 played against player #7. Before you protest that this is unfair to players #1 and #6, note that all those six players have in fact played a round robin among themselves. That is exactly the point of a round robin – every player faces all the other opponents exactly once. If you were to leave player #7 in and give the opponents a full point for the unplayed games, then you would actually be giving a majority of the players a free point. That would be unfair to the minority of players who actually did play against the withdrawn player.
Note that any games played by the withdrawn player still do count for rating purposes. So, in our example, you would need to create a “side games” section and report the results of the games players #1 and #6 played in that section.
Your discomfort about having “two players with byes” comes from thinking about the tournament as though it were a Swiss. Remember, one of those players is sitting out the round because it is that player’s turn to not have an opponent. You might be thinking that you should deal with “two players with byes” by pairing these two players. Don’t! Think about it: those two players will be paired in a different round (or may already have been paired) because a round robin guarantees that every player faces every other player exactly once. If you pair the two players, then they will face each other twice. (Of course, you could let them play a separate side game for rating purposes if they are so inclined, but that game does not count for tournament standing or prizes.)
Finally, do not forget to apply the color corrections in rounds five, six, and seven if a player withdraws before completing four games. (See the footnote at the bottom of the pairing table.)
If you are lucky you might be able to renumber the players so you can reduce the number of rounds by 2 while maintaining the order and results of the early rounds. If need be you can start one player with two whites and someone else with two blacks–that used to be the norm and is better than having two constant byes in each round.
The original Berger tables had, for example in a ten player tournament, players 1-5 had white against 10-6 respectively. After 1 had white against 10, he would have white against 2. Player 6 starts with black against 5 then has black against 10. Both Crenshaw and I corrected that problem by having players 2-5 starting with black against 9-6, but Crenshaw also renumbered almost every player in order to do that.
My pairing generator is here and this is a suggested rewrite of the Round Robin chapter of the rulebook with dropout tables.