New “Auto” number of matches for Swiss Tournaments

Tournaments organization / Organisation des tournois
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Corwin007
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Corwin007 »

Looks like for whatever reason Auto gives one more round than actually needed based on number of players (yes, it doesn't care about there being a sole leader even earlier, just about total number of players). The fact that it gets stuck is a new problem. I'll add this example to my bug.
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Corwin007
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Corwin007 »

Meeplelowda wrote: 13 July 2025, 17:10 Any idea why this one is showing 5 matches for only 13 players? You should only need 4 for up to 16 players, assuming no game can be tied. Is it also adding matches in anticipation that ties may need to be broken?
Where do you see it's going to be 5 matches? In the percentage completed? You could add this to the bug I posted just below your post, and upvote it.
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Meeplelowda
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Meeplelowda »

Corwin007 wrote: 17 July 2025, 09:16
Meeplelowda wrote: 13 July 2025, 17:10 Any idea why this one is showing 5 matches for only 13 players? You should only need 4 for up to 16 players, assuming no game can be tied. Is it also adding matches in anticipation that ties may need to be broken?
Where do you see it's going to be 5 matches? In the percentage completed? You could add this to the bug I posted just below your post, and upvote it.
Before the tournament started it said "tournament draw + 5 matches" in the "Tournament agenda" section. I don't know why that section gets erased once the tournament starts.
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Corwin007
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Corwin007 »

Got it. So yeah, it looks like for whatever reason Auto isn't calculating the number correctly.
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BananaHarambe
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Re: New “Auto” number of matches for Swiss Tournaments

Post by BananaHarambe »

https://boardgamearena.com/tournament?id=389875 hey the 3 player Faraway tournament with 192 players completed as it should. I thought there was a bug because it said 100% complete, but I just missed that there was 1 match remaining.

Tournament ended correctly afterwards.

6 rounds for 3 players is 1 more than it should based on log3(192) < 5, round up would be 5 matches. Seems like the "1 more than expected" is correct and factors in player count.
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Mathew5000
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Mathew5000 »

Banana's 3p Faraway tournament allowed 2p games where necessary. I wonder if that's why it went six rounds instead of five.

I wish the devs would just share the algorithm here, although it's kind of fun to figure it out from the data.
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BananaHarambe
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Re: New “Auto” number of matches for Swiss Tournaments

Post by BananaHarambe »

Mathew5000 wrote: 17 July 2025, 20:30 Banana's 3p Faraway tournament allowed 2p games where necessary. I wonder if that's why it went six rounds instead of five.

I wish the devs would just share the algorithm here, although it's kind of fun to figure it out from the data.
Perhaps allowing 2p games affected it. I saw no reason to force 3p and have skipped players.

If it were a 2p tournament it should have been 8 matches.

Also, how does this explain extra rounds for 2p Auto Swiss?
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Corwin007
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Corwin007 »

Yeah, I don't think allowing 2p games if not enough players in 3p would create the problem.
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Mathew5000
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Mathew5000 »

I have tried unsuccessfully to set up a Swiss tournament with the "Auto" option set, that would end after the first round. For example, this ongoing tournament: https://boardgamearena.com/tournament?id=417177 A 3p game with only three entrants in the tournament. By the formula, it should have ended after the first round. Game 1 had a clear winner, but the tournament still continued to step 2. The order of finish in game 2 was the exact opposite to that of game 1, and therefore the standings are tied after game 2 at 4 swiss points apiece. Game 3 is ongoing. But what exactly is the reason it did not stop after game 1?

Here's one from a couple of months ago: https://boardgamearena.com/tournament?id=383402 A 2p game with 4 entrants in the tournament. It stopped after round 2, as you would expect from the formula, with 1 undefeated player out of the four.
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Meeplelowda
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Re: New “Auto” number of matches for Swiss Tournaments

Post by Meeplelowda »

Mathew5000 wrote: 03 August 2025, 03:32 I have tried unsuccessfully to set up a Swiss tournament with the "Auto" option set, that would end after the first round. For example, this ongoing tournament: https://boardgamearena.com/tournament?id=417177 A 3p game with only three entrants in the tournament. By the formula, it should have ended after the first round. Game 1 had a clear winner, but the tournament still continued to step 2. The order of finish in game 2 was the exact opposite to that of game 1, and therefore the standings are tied after game 2 at 4 swiss points apiece. Game 3 is ongoing. But what exactly is the reason it did not stop after game 1?

Here's one from a couple of months ago: https://boardgamearena.com/tournament?id=383402 A 2p game with 4 entrants in the tournament. It stopped after round 2, as you would expect from the formula, with 1 undefeated player out of the four.
We now have several examples of it going one round more than is needed to have a guaranteed undefeated player if no ties are possible. I think they have just baked in an extra round to deal with a possible tie without checking to see if there actually is one. I know it's easy to say when you're not doing the coding, but it doesn't seem like that check would be very hard to implement.
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