9 players, 8 rounds, groups of 3 - no repetition?

[dmleach]

Thanks to your fantastic website I see that it's possible to arrange 9 players into a 3 groups of 3 for a round robin tournament:

(1 2 3) (4 5 6) (7 8 9)
(1 4 7) (2 5 8) (3 6 9)
(1 6 8) (2 4 9) (3 5 7)
(1 5 9) (2 6 7) (3 4 8)

I'm planning a double round robin tournament over eight rounds. Is it possible to arrange the players the second time through so that none of the threesomes from the first four rounds are repeated? That is to say: since 1 and 2 played 3 the first time they faced one another, can we arrange the schedule so that 1 and 2 face a different player in their rematch, and so on?

Thanks so much!

[Ian Wakeling]

The following 4 rounds should complement the 4 rounds above with no repeated threesomes.

(1 2 9) (3 4 5) (6 7 8)
(1 3 6) (2 4 7) (5 8 9)
(1 5 7) (2 3 8) (4 6 9)
(1 4 8) (2 5 6) (3 7 9)

HTH,

Ian.

[dmleach]

Excellent! I was close to puzzling it out on my own, but couldn't quite make it work. I really appreciate the help!