Round Robin Tournament Scheduling

28 player mixed doubles no repeat round robin

bobmasi · 10 · 3992

bobmasi

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on: January 16, 2022, 08:28:46 AM
Hello,
Looking for help in organizing a One Day platform tennis tourney.
28 players, 14 men and 14 women.  Mixed doubles with no repeat of partner or opponent.
We have 3 courts to play on.


Ian Wakeling

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Reply #1 on: January 17, 2022, 03:53:00 AM
How many rounds do you want to play?  7 rounds is good because you should be able to arrange that everyone has exactly 3 games.


bobmasi

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Reply #2 on: January 17, 2022, 08:22:50 AM
Thanks for the reply Ian.  I would like each player to play 5 rounds.  Need schedule for that.
I tried to use your excel scheduler but I could not find how to set it for mixed doubles (just works for singles)??


Ian Wakeling

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Reply #3 on: January 17, 2022, 11:59:52 AM
I think the following will give each player 5 games, and at the same time all partners and opponents should be different people:


(M1 F1 v  M8  F8)  (M7 F7 v M14 F14)  (M6 F6 v M13 F13)
(M5 F5 v M12 F12)  (M4 F4 v M11 F11)  (M3 F3 v M10 F10)
(M7 F5 v M13 F11)  (M6 F4 v M12 F10)  (M5 F3 v M11  F9)
(M4 F2 v M10  F8)  (M3 F1 v  M9 F14)  (M2 F7 v M8  F13)
(M6 F2 v M11 F14)  (M5 F1 v M10 F13)  (M4 F7 v M9  F12)
(M3 F6 v  M8 F11)  (M2 F5 v M14 F10)  (M1 F4 v M13  F9)
(M2 F2 v  M9  F9)  (M1 F6 v M14 F12)  (M7 F3 v M12  F8)
(M5 F6 v  M9 F10)  (M4 F5 v  M8  F9)  (M3 F4 v M14  F8)
(M2 F3 v M13 F14)  (M1 F2 v M12 F13)  (M7 F1 v M11 F12)
(M4 F3 v M14 F13)  (M3 F2 v M13 F12)  (M2 F1 v M12 F11)
(M1 F7 v M11 F10)  (M7 F6 v M10  F9)  (M6 F5 v  M9  F8)
(M6 F7 v M10 F11)  (M5 F4 v  M8 F14)
« Last Edit: January 17, 2022, 12:01:28 PM by Ian Wakeling »


bobmasi

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Reply #4 on: January 17, 2022, 03:06:20 PM
Many Thanks Ian.  If its not too much trouble can you also provide the same thing but for 24 total
players (12M and 12W).  Not sure on final count so need a backup option.


Ian Wakeling

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Reply #5 on: January 18, 2022, 06:59:01 AM
When there are 24 players the method I used has problems.  The best I can do is 3 games each as follows:

(M1 F4 v  M8 F11)  (M3 F2 v M11 F12)  (M5 F6 v  M9  F8)
(M4 F3 v M12  F7)  (M2 F1 v M10  F9)  (M2 F5 v  M7 F10)
(M5 F2 v M10  F7)  (M1 F6 v  M9 F10)  (M6 F5 v  M8  F9)
(M3 F4 v  M7 F12)  (M2 F3 v M12 F11)  (M4 F1 v M11  F8)
(M3 F1 v M12 F10)  (M4 F5 v  M8  F7)  (M1 F3 v M10 F12)
(M2 F6 v M11  F9)  (M5 F4 v  M7  F8)  (M6 F2 v  M9 F11)


bobmasi

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Reply #6 on: January 18, 2022, 02:14:29 PM
Ian, I saw in another post reference you had a schedule for 24 players (12M 12W) on 6 courts that had them playing all 11 games, but you stated that you could just pick anything less than the 11 games (ie. only 5 games) and retain the non-repeat. I can't see a reason I couldn't use this.  It's also nice because it also works well for 3 courts and appears to allow for everyone to play exactly every other game?   When you sent the 28 player schedule it had some players having big time gaps and others playing multiple back to backs.  I thought I could improve on that manually but it was too hard.  Is there a way to redo that achieving closer to an "every other game" rotation for all/most players?  Thanks Again.


Ian Wakeling

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Reply #7 on: January 19, 2022, 03:48:56 AM
You are referring to the spouse avoiding schedule here.  I had not considered this because I thought you were asking for all the players a player meets, either as partner or opponent, to be different.  If you don't mind players meeting the same person twice, once as partner and once as opponent, then as you have found out, things get easier.  It works especially well for 24 players as the standard schedule has 6 courts per round, so each round divides nicely into to two sub-rounds on 3 courts with each player exactly once (note it is not the same 12 players alternating off and on, so there will still be some back-to-back games and some players with 2 byes in a row, but there should be no runs of 3 or more back-to-back games).  For the 28 player schedule I did start with a schedule for 7 courts, but this does not divide so nicely.  I think it will have the property that all players play 3 times in the first 7 rounds, and twice in the last 5 rounds.  Sorry, I don't have any way of reducing the frequency of back-to-back games here, but you could try automating what you were trying manually, and optimize the order of the rounds with a computer.
« Last Edit: January 19, 2022, 03:51:03 AM by Ian Wakeling »


bobmasi

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Reply #8 on: January 19, 2022, 07:31:14 AM
At the risk of driving you completely insane....could I ask you for a schedule for 26 players (13M 13W) also for 5 games.  It is OK for a player to play against a former partner if that simplifies things.  My player count is quite shaky and forcing multiple options!    Appreciated


Ian Wakeling

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Reply #9 on: January 20, 2022, 05:16:37 AM
26 players is not good as it is not a multiple of 4, so it is actually impossible to give everyone the same number of games (unless you make them play 12 games each which presumably is too many for one day).  I have made this schedule:

[(M08 F01):(M02 F09)] [(M01 F06):(M09 F04)] [(M07 F11):(M03 F12)]
[(M13 F03):(M10 F07)] [(M06 F08):(M04 F02)] [(M12 F13):(M11 F10)]
[(M04 F10):(M11 F05)] [(M10 F02):(M05 F13)] [(M03 F07):(M12 F08)]
[(M09 F12):(M06 F03)] [(M02 F04):(M13 F11)] [(M08 F09):(M07 F06)]
[(M05 F11):(M12 F06)] [(M11 F03):(M06 F01)] [(M04 F08):(M13 F09)]
[(M10 F13):(M07 F04)] [(M03 F05):(M01 F12)] [(M09 F10):(M08 F07)]
[(M06 F12):(M13 F07)] [(M12 F04):(M07 F02)] [(M05 F09):(M01 F10)]
[(M11 F01):(M08 F05)] [(M04 F06):(M02 F13)] [(M10 F11):(M09 F08)]
[(M07 F13):(M01 F08)] [(M13 F05):(M08 F03)] [(M06 F10):(M02 F11)]
[(M12 F02):(M09 F06)] [(M05 F07):(M03 F01)] [(M11 F12):(M10 F09)]
[(M01 F01):(M02 F02)] [(M03 F03):(M04 F04)]

However, F1 & M2 oppose twice and M5 & F5 have only 4 games.  It's probably possible to have a schedule without the repeated opposition pair, but I can't see an easy way to get there.