I just had a tournament start that I set up and it appears to have dropped all the dan level players. As far as I know, this should not have happened with the settings I used. Here is the tournament. What did I miss? Why were they dropped? https://online-go.com/tournament/32528

I know practically nothing about the mechanics of how these tournaments are run, but I hate to see your query completed ignored. Some thoughts. You do not say how many dan players disappeared. If it was two or three, they may have coincidentally left because they did not see sufficiently interesting competition. Or perhaps some other, more interesting, competing tournament â€śstoleâ€ť them away from you.

The only thing I could imagine that may be amiss is the McMahon bars. I had to look this up in SL to find out what they areâ€”so judge these comments accordingly. Since your bars donâ€™t mention dans, is it possible that the system simply stopped at 1k? Based on SL, this shouldnâ€™t happen, as everything above 10k should be grouped, but maybe the computer doesnâ€™t understand that. Just a thoughtâ€¦

I appreciate the effort at an answer. It took out all of them and I think there was about 5-6 of them. Iâ€™ve started dozens of tournaments before this one and itâ€™s never happened before. I donâ€™t understand the McMahon bars either, but I donâ€™t think that setting is my culprit. I didnâ€™t change the maximum rank allowed. They had been signed up right until just before it started. Very odd.

FWIW the McMahon bars describe the range of ranks over which the playersâ€™ starting points tally changes.

So for example if the bars are set to 20 kyu - 10 kyu, all players ranked 10kyu or higher start with zero points and all players ranked lower than 20kyu start with some negative score, say -8 for the sake of argument (I donâ€™t know how this number is decided actually). All the players between those ranks start with some points value between 0 and -8. So an 11kyu might start with -1 points and and 19 kyu with -7 points, 15kyu with -4 and so on (this is just an approximation but you get the idea I hope).

Then in each round players are placed in groups with players on the same number of points as them and you get a point for each win. This system makes it nearly impossible for a low ranked player to win the tournament but the idea is that if they were strong enough to win they would have a higher rank already. The point of doing this is to maximise the number of competitive games in the tournament so you are not wasting the first round by having dan players beat up on DDKs.

Anyway, your bars shouldnâ€™t have caused the problem with this tournament.

Thatâ€™s the theory. It seems to work fine in simultaneous McMahon tournaments. In normal McMahon tournaments you get the seed points as described but the placing in groups does not happen. Which makes this tournament type a bit pointless. (I canâ€™t be sure itâ€™s happening in all of them, but at least in all that Iâ€™ve seen so far.)