Round Robin Tournament Scheduling

"Whist" with two player pools, limited rounds, and 4 courts

J0E · 4 · 126

J0E

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Hello,

first of all, I'm from Germany, so my English might be weird at times. Also, the tournament format I will describe is seemingly rare (I couldn't find any calculators or pre-calculated tables for it on the internet), but it seems to be related to a "Whist" schedule, so I'm hoping this is the right place to ask.

At my tennis club, we have a tradition to do a just-for-fun doubles tournament at the start and end of the season. It works like this:

  • All players are divided into two player pools: good players (A-players) and not-so-good players (B-players). 
  • Then, doubles are set up in a way so that there is always an A-player playing together with a B-player. The doubles are timed to 20 minutes, with 10-minute breaks, so that everything can be played in a single day.
  • Everyone is supposed to have 4 to 5 matches, depending on how many players there are.
  • Here's the difficult part: If possible, you should never have the same partner as well as never the same opponent twice. Playing with someone you played against before is acceptable, but should be avoided if the number of players allows for it.
  • All of this takes place on 4 courts, allowing for 16 players at a time.
  • The A- and B-players with the most wins get a small prize.

With an uneven number of players, some players will have unrated bonus matches. It's easy to adjust a table for an even number of players for that. What makes organizing this tournament so damn frustrating is the fact that there are always some people that don't show up (because they forgot about it), or cancel last minute, on the morning of the tournament. We often have to scrap the pre-made tables, and improvise. 
Which is why I am in need of a tournament table for every number of players from 16 to 32.


To summarize the requirements:

  • Two player pools, from which each doubles team is made up.
  • No reoccuring partners or opponents.
  • 4-5 matches for each player.
  • 4 courts.
  • 16 to 32 players


An (imperfect) example for 24 people:

A-players: A, B, C, D, E, F, G, H, I, J, K, L
B-players: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

court 1        court 2        court 3          court 4

A1 vs E5     B2 vs F6       C3 vs G7       D4 vs H8     round 1

I9 vs A2      K10 vs B3     L11 vs C4     J12 vs D5     round 2

E6 vs I10     F7 vs K11     G8 vs L12     H9 vs J1       round 3

A3 vs E7      B4 vs F8       C5 vs G9      D6 vs H10     round 4

I11 vs A4     K12 vs B5     L1 vs C6       J2 vs D7       round 5

E8 vs I12      F9 vs K1      G10 vs L2     H11 vs J3     round 6
 

I'd love to make a calculator for this in excel, but the complexity is beyond me. And I couldn't find anything for this tournament mode on the internet - the closest thing was the "Whist" setting in the rounds viewer on this website. And I don't know how to best modify it to match my requirements.
Maybe there is a certain English word for this tournament mode, so I can find what I need with Google? The German word Schleifchenturnier had no usable results.

Any help or suggestion is appreciated! Many thanks!


Ian Wakeling

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Reply #1 on: October 02, 2022, 12:56:05 PM
Hello,

I can only be of limited help, as what you really want is software that can optimize a schedule for any given number of players - and I am not aware of anything suitable.  I can see that for a lot of choices of the number of players there will be no good schedules - for example it will often not be possible to give every player the same number of games.   What I can do it point out were a perfect schedule might exist, which will be for a multiple of 4 players.  If you are logged into the forum and you look at my 1st reply here then you can download an Excel file with foursome schedules.  You can rearrange each foursome game (AABB) into a doubles game (AB vs AB) any way you like, and discard the columns higher than foursome 4, this will give you a schedule where everyone has 4 matches and all partners and opponents are different - unfortunately this does not give you a solution for 16 or 24 players.


J0E

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Reply #2 on: October 02, 2022, 05:42:44 PM
Alright, thanks anyways. In that case, as soon as I have more free time, I'll come up with self-made tables for the other possible numbers of players and post them here, in case anybody encounters this problem again.


BigDonkey

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Reply #3 on: October 18, 2022, 01:58:39 PM
I do something similar, and if you're willing to make a compromise, you can make it work for any number of players as long as you play exactly 4 rounds. An even number of players always works out, while with an odd number of players you will have to have one match be all players from the B-pool play together. It's good enough for my purposes of keeping all the games somewhat evenly matched and getting everyone 4 games.

17 players:

Rd 1: A1B7 vs A3B4     A4B2 vs A7B3     A5B8 vs A8B6     A6B5 vs A2B9     (B1)

Rd 2: A4B3 vs A5B9     A1B2 vs A8B7     A2B8 vs A7B1     A3B5 vs A6B4     (B6)

Rd 3: A3B9 vs A7B2     A4B1 vs A6B7     A1B5 vs A5B6     A2B3 vs A8B8     (B4)

Rd 4: A2B5 vs A3B7     A5B4 vs A7B8     A6B1 vs A8B2     A1B6 vs A4B9     (B3)

Rd 5: B1B3 vs B4B6