Round Robin Tournament Scheduling

Recent Posts

61
Requests / Re: Round Robin Schedule For Changing Teams
« Last post by Ian Wakeling on August 21, 2024, 02:59:40 AM »
Hi Nathan,

The 8 player scenario is a standard one where it is possible to arrange that everyone plays with each other player once, and against each other player twice.  It is called a Whist schedule in combinatorial math, and you can find an example by following the "visit the pages that inspired the forum" link near the top of the page, and then following Whist tables and dialling up 8 items.  You can use the same tool to get a 15 round schedule for 16 players, however I don't see that there is an easy way to cut it down to 6 rounds, instead I have a program (not Excel) that implements a search algorithm that can find a solution.  I have put this below.

  (15 13 v  4 14)  (10 16 v 11  5)  ( 6  7 v  1 12)  ( 3  9 v  2  8)
  ( 2 12 v  5  4)  ( 9  7 v 11 14)  (10 15 v  1  3)  ( 6  8 v 13 16)
  (14 16 v 12  3)  (13 11 v  2  1)  ( 5  9 v 15  6)  ( 8 10 v  7  4)
  ( 3  7 v 13  5)  ( 2 14 v 10  6)  ( 4  1 v 16  9)  ( 8 12 v 11 15)
  ( 8  5 v 14  1)  (16 15 v  2  7)  ( 9 10 v 12 13)  ( 3  6 v  4 11)
  ( 4  2 v  1  7)  ( 8 13 v  5 12)  (10  3 v  9  6)  (16 11 v 14 15)

I can offer to try other combinations of players, courts and rounds.

Best regards,

Ian
62
Requests / Round Robin Schedule For Changing Teams
« Last post by NTLKnight on August 20, 2024, 06:36:57 PM »
I host beach volleyball tournaments on a regular basis, most of the tournaments are regular "round robin" style and played in a single day on 2-4 courts, but recently I've been doing a tournament style where partners switch for each game...giving everyone a chance to play with every other player, as a team. In beach volleyball teams are comprised of 2 players, so Game 1 might be Players 1/5 vs Players 3/8 and Game 2 might be Players 5/2 vs Players 7/3, etc.


My challenge is not necessarily figuring out which team should play *against* which team, but rather in balancing *how many times* a certain player plays *against* another *player*.  I tried using the Ian Balanced Round Robin Excel spreadsheet to help randomize teams (and it's an amazing tool, BTW!), but I'm not sure I could figure out how to also factor in the amount of times a player would play *against* other players...so as to have a balanced amount of games where all players (as much as possible) will play against *most* other players, at least once...and not play against the same players a great number of times. I've spent so much time on this, including using AI to help...and while AI *can* create a nice random round robin pairing of partners, it doesn't seem to be able to add the element of balancing the number of times players will play against other players. Further, I've tried several online round robin tools and calculators, but haven't been able to find one that deals with the above-mentioned specifics.

Over the last year or 2 I've started chiseling away at an Excel spreadsheet to help figure this out...and after dozens of iterations, I find myself manually assigning each team...to try as much as possible to control who each player plays against. It's tedious and time consuming...and I'm mainly using Conditional Formatting to show me repeats. But even now I feel like missing the mark of doing this the right way and maybe it's time I ask for help!

Here's a look at my Excel spreadsheet for a Round Robin schedule that has:
  • 8 Players (4 teams)
  • 2 Courts
  • Each Player plays *with* every other player once (requiring 7 games for this to happen)
  • And "trying" to balance the amount of times each player plays *against* the other players.




When it comes to creating bigger tournaments (16 players/8 teams/4 courts), it's easier...because not every player gets to play with every other player (because of a lack of time in a 3-4 hour tourney)...so hand-picking the numbers based on a random drawing makes it easier to not have one player play against another player more than 1 or 2 times...



Any help along these lines would be greatly appreciated!  Ideally a randomizer/generator like the one that Ian built, that allows for a few variables like:

  • Number of Courts
  • Number of Players
  • Team size (normally 2, but sometimes 4)
  • Number of Games
  • *** Then Randomizes players into teams...while at the same time:
  • *** Balances the number of times each player plays against another player (trying to keep it as equal as possible).

Thank you for reading this far...and for any help!

Best Regards,
Nathan
63
Requests / Re: 8 Team Round Robin- Scenario
« Last post by Ian Wakeling on August 03, 2024, 10:39:19 AM »
If we compromise on the format a little and sometimes only send 2 teams to a venue, then it can be done in 6 rounds.

    Site 1     Site 2       Byes
  (4  2  3)  (6  7  5)    [1  8  -]
  (3  8  -)  (1  2  5)    [4  6  7]
  (3  7  1)  (5  8  4)    [6  2  -]
  (4  1  7)  (2  6  -)    [5  8  3]
  (3  5  -)  (1  6  8)    [7  2  4]
  (8  2  7)  (4  6  3)    [1  5  -]

So above team 3 has 1 bye while the other teams have 2 byes each. There are also two repeated games in the schedule, so:

In round 4 the match up between teams 1 & 7 does not need to be played.
In round 6 the match up between teams 3 & 4 does not need to be played.
64
Requests / Re: 8 Team Round Robin- Scenario
« Last post by mjohn on August 03, 2024, 08:24:56 AM »
Unfortunately, this happens after school and a time issue have 4 teams at each site. Any other thoughts?
65
Requests / Re: 8 Team Round Robin- Scenario
« Last post by Ian Wakeling on August 03, 2024, 07:11:18 AM »
A schedule like this is not possible, it would be better not having byes and sending 4 teams to each site.
66
Requests / Re: 11 Team 10 Game Beer Olympic Schedule
« Last post by Ian Wakeling on August 03, 2024, 07:04:07 AM »
Here are two schedules that should work.  They are symmetric, so rows & columns can be assigned to rounds & games either way around.

14 teams (A to N), 7 rounds/7 games
(K G) (B N) (J D) (C H) (A L) (F E) (I M)
(F N) (I D) (C L) (A G) (K E) (B M) (J H)
(J E) (A M) (F H) (B L) (I G) (C N) (K D)
(I L) (C E) (K M) (F D) (B H) (J G) (A N)
(C M) (K H) (B G) (I E) (J N) (A D) (F L)
(A H) (F G) (I N) (J M) (C D) (K L) (B E)
(B D) (J L) (A E) (K N) (F M) (I H) (C G)

16 teams (A to P), 8 rounds/8 games
(A P) (C O) (L B) (H K) (I J) (M N) (F G) (E D)
(H D) (L G) (C J) (A N) (F B) (E K) (I O) (M P)
(M J) (I N) (F D) (E G) (C P) (A O) (L K) (H B)
(F N) (E J) (M G) (I D) (H O) (L P) (A B) (C K)
(C G) (A D) (H N) (L J) (M K) (I B) (E P) (F O)
(E B) (F K) (I P) (M O) (L D) (H G) (C N) (A J)
(L O) (H P) (A K) (C B) (E N) (F J) (M D) (I G)
(I K) (M B) (E O) (F P) (A G) (C D) (H J) (L N)
67
Requests / Re: Bjerring Tournament
« Last post by Ian Wakeling on August 03, 2024, 06:18:21 AM »
Is 5 rounds OK where everyone has 4 games and one bye?  For example:

      Court 1              Court 2              Court 3              Court 4            Byes
(23 21 5 v 13 12 26) (20  7 27 v 14 11  6) (1 10 29  v 4 28 17) (22  8 18 v 19 3 25) [2 16 15 24  9 30]
(24 22 1 v 14 13 27) (16  8 28 v 15 12  7) (2  6 30  v 5 29 18) (23  9 19 v 20 4 21) [3 17 11 25 10 26]
(25 23 2 v 15 14 28) (17  9 29 v 11 13  8) (3  7 26  v 1 30 19) (24 10 20 v 16 5 22) [4 18 12 21  6 27]
(21 24 3 v 11 15 29) (18 10 30 v 12 14  9) (4  8 27  v 2 26 20) (25  6 16 v 17 1 23) [5 19 13 22  7 28]
(22 25 4 v 12 11 30) (19  6 26 v 13 15 10) (5  9 28  v 3 27 16) (21  7 17 v 18 2 24) [1 20 14 23  8 29]
68
Requests / 8 Team Round Robin- Scenario
« Last post by mjohn on August 02, 2024, 05:13:25 PM »
Good day
I am seeking assistance with an 8 team round robin for volleyball. there will be 2 seperate sites- 3 teams at each site, and 2 teams receive a bye. Appreciate any assistance. Stumped
69
Requests / Re: 11 Team 10 Game Beer Olympic Schedule
« Last post by Aveon on August 01, 2024, 01:53:17 PM »
Can you make a setup for 14 teams with 7 or 8 stations/posts, also a setup for 16 teams with 8 stations/posts? Thanks in advance!

70
Requests / Bjerring Tournament
« Last post by Hannah Berry on July 30, 2024, 10:08:04 PM »
I want to make a Bjerring tournament where they play triples on 4 courts. I want them to be paired up with different people almost every time. I will have 30 girls.