Round Robin Tournament Scheduling

Schedules - You must register to Post and Download => Requests => Topic started by: xman15 on December 04, 2007, 11:20:03 AM

Title: A players and B players
Post by: xman15 on December 04, 2007, 11:20:03 AM
I have a tourrnament with 8 A players and 8 B players.
In each round, each of the four games teams an A player with a B player vs. an A player and B player.
I would like to minimize the number of times you play with or against the same players, with 7 or 8 rounds.
Title: Re: A players and B players
Post by: Ian Wakeling on December 05, 2007, 06:05:32 AM
This is a similar problem to that of a mixed doubles competition.  There are standard schedules called spouse avoiding mixed doubles tournaments where you parnter and oppose everyone except your spouse exactly once.

(H1 W4 v H2 W7) (H3 W1 v H4 W5) (H5 W3 v H6 W8) (H7 W6 v H8 W2)
(H1 W7 v H3 W6) (H2 W5 v H7 W3) (H4 W2 v H5 W8) (H6 W1 v H8 W4)
(H1 W6 v H4 W8) (H2 W4 v H8 W5) (H3 W7 v H5 W2) (H6 W3 v H7 W1)
(H1 W3 v H5 W4) (H2 W8 v H6 W7) (H3 W5 v H8 W6) (H4 W1 v H7 W2)
(H1 W5 v H6 W2) (H2 W1 v H3 W8) (H4 W3 v H8 W7) (H5 W6 v H7 W4)
(H1 W8 v H7 W5) (H2 W3 v H4 W6) (H3 W2 v H6 W4) (H5 W7 v H8 W1)
(H1 W2 v H8 W3) (H2 W6 v H5 W1) (H3 W4 v H7 W8) (H4 W7 v H6 W5)

So I think the above gives you an option for 7 rounds of play, and you could play something like:

(H1 W1 v H2 W2) (H3 W3 v H4 W4) (H5 W5 v H6 W6) (H7 W7 v H8 W8)

if you wanted an eighth round.
Title: Re: A players and B players
Post by: schedulecc on November 21, 2022, 01:41:51 PM
This is almost perfect for my mixed doubles scenario, but is there a schedule that does 8 rounds on four courts that does have everyone pair with and play against all players (no spouse avoidance)?
Title: Re: A players and B players
Post by: schedulecc on November 21, 2022, 03:23:15 PM
Sorry, ignore the request.  I had mis-entered the schedule, it is perfect for 8 rounds.  This site is AWESOME, thank you so much!!
Title: Re: A players and B players
Post by: dwfortner on April 22, 2024, 04:23:10 PM
Hey, did you ever come up with an 8-week schedule for the mixed doubles that is not spouse avoiding?
I found a table for 16 players (8 women 8 men) in the paper Ian Co-wrote about generalizing the Spouse avoiding and strict mitchell mixed doubles round robin.
It shows a table for strict Mitchell Mixed Doubles Round Robin (strict MMDRR( 8 ) ), which has been really helpful, but I would love to know if someone worked through what an 8-round schedule of those matches would look like, with all players playing each round, if that's even possible.
Title: Re: A players and B players
Post by: Ian Wakeling on April 23, 2024, 01:48:26 PM
Hi, thanks for looking at the paper.  My best guess is that the schedule you want does not exist.  What I know is that the construction shown in the paper for larger schedules of 20, 24, 28,... players does not work for 16, and I have tried without any success to find a 16 player schedule by computer search. It is possible to have 16 players in 11 rounds on 3 courts (example 2.11), but of course there will be people with byes in every round.
Title: Re: A players and B players
Post by: dwfortner on April 24, 2024, 11:31:15 AM
Thanks for the feed back. I figured there was no solution for the 8-round 4 court schedule. 
We've landed on a sort of hybrid schedule where there's a mix of multiple opponents. Similar to the Spouse avoidance with the additional round.
Thanks for the work you've done in the analysis and proof of all that. It's really hard to find stuff out there for these types of schedules.
To me that's surprising. I guess the way sports are going (pickleball, for example), it's more the case where you're either going to have a set partner or you're going to mix with everyone (so, like a 16-player whist) and most people don't care about actual mixed doubles.
Again, thanks for the work and feedback, and generally making yourself available. THis forum is really cool. Nice work :)
Title: Re: A players and B players
Post by: dwfortner on April 24, 2024, 03:19:01 PM
Hey, I put together that schedule, I wanted to run it past my team to see if they liked the overall balance of it better (I do), and I did find one small error in that table showing the resolution for Example 2.11:
In the 6th row, columns 4 and 5, it works out if those are switched.
As in, for round 1, it should be M6F5 vs M2F3, not M6F4 vs M7F7 as both M7 and F7 are in the other 2 matches for round 1. Otherwise, the rest of the table works out for 10 2/3 rounds.
Here's what I mean:
(https://i.imgur.com/I7M37O6.png)(https://i.imgur.com/xxinHOg.png)