Look, I do agree with what you and @richyfourtytwo are saying, but I believe the reason that particular tournament didn’t reflect what you called the spirit of McMahon pairing is the way it was configured.
By all means, ensuring that every player has the actual possibility of winning may not be the [main] purpose of the McMahon system, but I don’t think it follows that it’s reasonable to have a tournament in which it’s virtually impossible for someone to win.
“Order the field of players by strength, divide the field into bands of players based upon number of rounds and the distribution of players strengths.” Why would we care about the number of rounds if not for an underlying, implicit understanding that a tournament should be at least potentially winnable for each participant?
The server seems to agree that said principle comes first, McMahon pairing ot not, and uses the number of rounds/matches and the potential score as the main parameter when generating the tournament—to the point of ignoring the intended band division when it’s incompatible with that.
Think about what you would have ended up with if that weren’t the case. We’re talking about a single-rank-band McMahon tournament (I would get back to this later). Suppose the only consideration were to ensure the participants only played inside their respective bands. It’s two games per round, right? So:
To begin with, two participants wouldn’t play in the first two rounds. Julko 17k and SebastianKenne 15k are both alone in their respective bars, so both get a bye in every match in the first round, Julko moving to the 16k bar and SebastianKenne to the 14k one… where they’re alone again, so same thing happens in round two.
Then there’s the bottom group, Cozy 25k and BlueFalcon 22k. Say they play and BlueFalcon wins. He moves to the 19k bar, Cozy stays. Aaaand that’s it for them in the tournament. They don’t get to play again. They’re both alone in their bands. They get a bye in the second match, Cozy stays in the bottom group with -9.5 points, BlueFalcon remains in the 19k band with -8.5 points. Comes round two, Cozy gets a bye and moves to the 18k bar… but Bluefalcon gets his own bye to and moves to the 17k bar, so they don’t meet. They’re still alone in their groups. Next round? Same thing.
Well, one could argue that that should still be possible, that everyone having the virtual possibility of winning the tournament not only isn’t the main focus of a McMahon, but that such a consideration can and should be disregarded if incompatible with an intended group division/number of rounds combo and ask @anoek to make the system reflect that…
But I believe OGS already has the system in place for tournaments that, borrowing again from your words, would respect the spirit of the McMahon pairing system, even, like in this particular case, with a small roster of players and an imbalance of ranks (
16 SDKs /
3 11k /
3 12k /
2 13k /
1 15k /
1 17k /
1 25k /
The issue is a lack of information (at least this is something I could’t find in the FAQ, for example): it’s not made clear that
McMahon uses the single-rank-band assigning method whereas
Simultaneous McMahon generates multiple-rank bands.
For the same roster and the same number of rounds, I believe that choosing
Simultaneous McMahon and a minimum group size of, say, 5 would lead to to the tournament you had envisioned. Three bars: SDKs (top group), a 11k-13k group and a 13k-25k bottom group, with respective initial scores of 0, -1 and -2, everyone would get to play, within the band, according to the group pairing method, and have the possibility of winning.
As for the single-rank-band
McMahon, it would work better with more players sharing the same rank—and, yes, I believe it would take a number of rounds/matches consistent with the resulting number of bands.