Round Robin Tournament Scheduling

Schedules - You must register to Post and Download => Requests => Topic started by: whitecollar91 on March 16, 2021, 05:11:15 PM

Title: 12 teams, 8 rounds (3x4 + 4x4)
Post by: whitecollar91 on March 16, 2021, 05:11:15 PM

Hello everyone,

I need to create a schedule for a tournament and its quite complex - at least for me ;)

There are 12 teams playing together in 8 rounds. 

Odd rounds are played: 3 games, 4 teams per game
Even rounds are played: 4 games, 3 teams per game

For example:

1st round

(ABCD) (EFGH) (IJKL)

2nd round

(AEI) (BFJ) (CGK) (DHL)


Satisfying solution is where teams play at least once with each other and max twice.

Thanks in advance for any help with that! 

Title: Re: 12 teams, 8 rounds (3x4 + 4x4)
Post by: Ian Wakeling on March 18, 2021, 05:12:34 AM

I think the following will work - you just need to alternate the two types of round to get the final schedule.

(10  8 11)  (4 12  7) ( 5  1  3) ( 6  2  9)
( 5  9 10)  (8  2  1) (11  4  6) ( 7  3 12)
( 3  5  1)  (6  7 10) ( 8  4  2) (11 12  9)
( 2  4  7)  (5 11  6) ( 9 12  1) (10  8  3)
 ( 3 11  2 12) ( 4 10  1  6) ( 7  5  8  9)
 ( 3 10  9  4) ( 5  7 11  2) ( 6  8 12  1)
 ( 1  9 11  4) ( 7  8  6  3) (10  5 12  2)
 ( 4 12  8  5) (11 10  1  7) ( 2  3  6  9)

Each team should have 2 teams who they play once, and 9 teams who they play twice.

Title: Re: 12 teams, 8 rounds (3x4 + 4x4)
Post by: whitecollar91 on March 19, 2021, 04:58:30 AM

Works fine, thanks a lot!

Title: Re: 12 teams, 8 rounds (3x4 + 4x4)
Post by: Ian Wakeling on March 20, 2021, 01:14:32 PM

I was looking again at this and spotted a repeated block in the schedule above, specifically teams 1,3 and 5 make up 2 of the blocks of 3.  So I offer the following alternative schedule:

 (1  5 10)  (2  4  8)  (3  6 12) ( 7  9 11)
 (1  2  6)  (3  9 10)  (4  8 12) ( 5  7 11)
 (1  5  8)  (2  7  9)  (3  6 10) ( 4 11 12)
 (1  8  9)  (2  3  5)  (4  6  7) (10 11 12)
  (1  6  9 11)  (2  4  5 10) ( 3  7  8 12)
  (1  3  4 11)  (2  9 10 12) ( 5  6  7  8)
  (1  4  7 10)  (2  3  8 11) ( 5  6  9 12)
  (1  2  7 12)  (3  4  5  9) ( 6  8 10 11)