# Algorithm for generating Jamboree chess pairings

Is there any algorithm that generates pairings for a Jamboree chess tournament, given the number of teams, the number of players in each team (no. boards) and the number of rounds? I've read somewhere that you can extrapolate the pairings for smaller numbers of teams to find those for more teams, but I'm slightly unsure how to do this?

We are trying to minimise the color difference so that in each round, the number of blacks for each team should be as close as possible to the number of whites. For odd numbers of teams, no player should have more than one up-float or more than one down-float. And, over all the rounds taken together, the number of up-floats for each team should be as close as possible to the number of down-floats.

• I would suggest adding some details on what the pairing rules are. Are we trying to minimize board differences, color differences, the number of times one team plays another, etc.?
– D M
Dec 8, 2023 at 23:54

## 2 Answers

I have found this web page with a number of Excel spreadsheets programmed for 3 round jamboree pairings for 4, 6, 8, 10, 12, 16, 20 board matches with 3 to 26 teams. Also 12 board 2 round jamboree and 12 board 5 round.

Maybe you can download the spreadsheets and work out the algorithms used if they don't cover your use case.

• Yes, I came across this site but it didn't include the exact configuration I wanted (12 10-player teams with 3 rounds). I tried a Google search on the algorithm used but I didn't get anything. It seems that this system is very niche and/or possibly outdated. Dec 11, 2023 at 16:20

Please don't enter into any correspondence related to this question before Wednesday 13 December; it is a question in the Ritangle competition which ends on 12/12/23. The poster knows that seeking such help is not within the rules. Thank you.

• This doesn't answer the question. It would be more appropriate as a comment Dec 11, 2023 at 23:54
• I am a chess tournament organiser that wants to be able to generate pairings quickly and efficiently, given I do not know exactly how many participants there will be, but have a rough idea. I am neither participating in this competition nor am I aware of it. Dec 12, 2023 at 15:07