Round Robin help needed

[Ian James]

Hi
I run an 18 team golf competition.
8 clubs supply teams.
One club has 4 teams, 2 clubs have 3 teams, 3 clubs have 2 teams and 2 clubs have 1 team.
The club with 4 teams is only used as a venue 3 times. 
All other clubs are used as venues equivalent to the number of teams entered.
I have been recycling draws created many years ago but need to create new draws as teams change.
I have one condition that none of the roundrobin generating websites allow me to manage.
I want to ensure that when 2 teams from the same club play one another, the match is played on their home course.
How can this be accomplished?
I have tried using AI with no success.
Any help would be greatly appreciated.

[Ian Wakeling]

It looks like you missed this schedule here that I made in June.  Not at all surprised about the AI, I have tried a few times with scheduling problems and simple probability problems and got nonsense back.

[Ian James]

Thankyou Ian. 
I did indeed miss your earlier reply.
How did you manage to come up with that?
Are there other combinations that would work?
I currently have 4 draws that I rotate.

[Ian Wakeling]

Hello Ian,

I used some software that I have written myself.  I can define 'fixed' games, so I pre-specified match-ups that must be played at certain times like this:

C1 ( 1  2) ( 3  4) (-----) (-----) (-----) (-----) (-----) (-----) (-----)
C1 (-----) (-----) ( 1  4) ( 2  3) (-----) (-----) (-----) (-----) (-----)
C1 (-----) (-----) (-----) (-----) ( 1  3) ( 2  4) (-----) (-----) (-----)
C2 ( 5  6) (-----) (-----) (-----) (-----) (-----) (-----) (-----) (-----)
C2 (-----) ( 5  7) (-----) (-----) (-----) (-----) (-----) (-----) (-----)
C2 (-----) (-----) ( 6  7) (-----) (-----) (-----) (-----) (-----) (-----) etc...

and then the algorithm tries to fit the non-fixed match-ups from the round robin into the remaining empty slots. I can try other scenarios if you wish.

Best regards,  Ian

[Ian James]

Could you provide this draw in an Excel spreadsheet please?
I can get enough variation by varying the club and team allocation i think.
Is your algorithm available as a download?

[Ian Wakeling]

Sorry, there is nothing downloadable that I can give you.  I have put the schedule in a Excel file as requested - it is attached, but you can only see it when you are logged in to the forum.

[Ian James]

Thankyou again.
I had managed to copy and paste it into Excel already using Ultraedit but that was long winded and laborious!
Are you creating these algorithms as programs or using Excel macros?
I would be interested to know more about the process you use to fill in the draw with matches already in place.
I have created the draws that I needed thanks to your help, this is just out of interest in the process!
Regards
Ian

[Ian Wakeling]

No need for Ultraedit, I just copy-pasted the schedule onto a worksheet and used the "Data/Text to Columns" feature to split it out into columns using "fixed width".

Yes, I am writing a program specifically to solve the problem and not using Excel. The process is not complex, I just fill up the schedule randomly to start and then start swapping pairs of non-fixed matches around to try to improve the quality of the schedule - where the quality is measured by how close it is to having each team once in each round of the schedule.

[Ian James]

Hi again Ian

Our situation has changed again.

Your help with a revised draw would be greatly appreciated.

New scenario;

8 clubs supply teams.
4 clubs have 3 teams, 2 clubs have 2 teams and 2 clubs have 1 team.
All  clubs are used as venues equivalent to the number of teams entered.
As previously, I have one condition that none of the roundrobin generating websites allow me to manage.

I want to ensure that when 2 teams from the same club play one another, the match is played on their home course.


Regards
Ian

[Ian Wakeling]

Hi Ian,

Have a look at the attached schedule in the Excel file.  I have highlighted the 'same-club' matches with the purple background.  Note that Club 6 only hosts once - there is no way of avoiding this unless either Club 7 or Club 8 never host.

Hope that helps,

Ian

[Ian James]

Thanks again Ian

Regards
Ian James