Round Robin help needed

[Ian James]

Hi 

I need to create a round robin draw for a golf competition that I run.

18 team round robin over 17 rounds each round all 9 matches are played at one golf club.

There are multiple teams from all but 2 of the clubs.

My difficulty with using most of the generator programs available, is the requirement for all derby matches to be played on home courses, 

when one club is played at in only 3 rounds but has 4 teams in the competition.

The other 7 clubs have 3, 3, 2, 2, 2, 1 & 1 teams respectively and are venues the same number of times as they have teams.

[Ian Wakeling]

Your competition could be scheduled as follows.  Assume the 8 clubs C1 to C8 have the following team numbers:

C1 = 1 2 3 4
C2 = 5 6 7
C3 = 8 9 10
C4 = 11 12
C5 = 13 14
C6 = 15 16
C7 = 17
C8 = 18

Then I beleive that the following schedule will meet your requirements.  The 17 rounds are the rows and the first column indicates the clubs who hosts:

C1 ( 1  2) ( 3  4) ( 8 11) ( 6 15) ( 5 16) (13 18) (10 17) ( 9 14) ( 7 12)
C1 ( 7 15) (11 16) ( 1  4) ( 2  3) ( 9 18) ( 5  8) (12 14) (13 17) ( 6 10)
C1 ( 8 18) ( 6  9) ( 5 12) (14 16) ( 1  3) ( 2  4) (13 15) ( 7 17) (10 11)
C2 ( 5  6) ( 2 13) (10 18) (11 14) ( 4 12) ( 7 16) ( 8 17) ( 1 15) ( 3  9)
C2 ( 3 12) ( 5  7) ( 9 17) ( 4  8) (13 16) (10 15) ( 1  6) (11 18) ( 2 14)
C2 ( 1 16) ( 4 11) ( 6  7) ( 3 18) (14 17) ( 2 15) ( 5 10) ( 8 12) ( 9 13)
C3 ( 8  9) (17 18) ( 1 14) (12 13) ( 2 10) ( 3 11) ( 4  7) ( 6 16) ( 5 15)
C3 ( 3 14) ( 8 10) ( 2 16) ( 9 15) (12 17) (11 13) ( 1  7) ( 6 18) ( 4  5)
C3 ( 5 18) ( 7 14) ( 9 10) ( 1 17) ( 4 13) ( 3  6) ( 2 12) ( 8 16) (11 15)
C4 (11 12) ( 1 18) ( 2  7) ( 5 13) (10 14) ( 6 17) ( 9 16) ( 4 15) ( 3  8)
C4 ( 4  6) ( 2  8) ( 3 17) ( 7 10) (15 18) (12 16) ( 9 11) ( 5 14) ( 1 13)
C5 (13 14) (12 15) ( 5 11) ( 7  8) ( 2  6) ( 1  9) ( 4 18) ( 3 10) (16 17)
C5 (10 13) (15 17) ( 4 16) (12 18) ( 1  8) ( 7  9) ( 3  5) ( 2 11) ( 6 14)
C6 (15 16) ( 3 13) (14 18) ( 4  9) ( 7 11) (10 12) ( 6  8) ( 1  5) ( 2 17)
C6 ( 4 17) ( 5  9) ( 3 15) (10 16) ( 6 11) ( 8 14) ( 2 18) ( 7 13) ( 1 12)
C7 ( 2  9) ( 6 12) ( 8 13) ( 1 11) ( 3  7) ( 5 17) (14 15) ( 4 10) (16 18)
C8 (11 17) ( 1 10) ( 6 13) ( 2  5) ( 8 15) ( 4 14) ( 3 16) ( 9 12) ( 7 18)

You will most likely want to reorder the rows/rounds so that the competition rotates around the 8 clubs to give variety week to week.  Teams appear in each of the 9 columns either once or twice, so you could use this feature to give some balance to the tee-off order.