12 team league playing at 2 locations?

[vh1vball]

Can anyone help me with the best way to schedule a 12 team volleyball league with a couple of conditions:

2 sites playing a maximum of 4 matches per night at each site. I think I'll probably need to have a few 3 match nights.  I believe I'll have 66 total matches, 33 at each location. I'm thinking 6 - 4 match nights and 3 - 3 match nights at each location. (The league has to be over in 9 weeks so that shouldn't be a problem)

Have the teams playing 2 matches per night as often as possible.

I've gotten half a season figured out, where each team has played 5 matches, but the second half of the season has got me stumped...

Thanks in advance for any help!

[Ian Wakeling]

This problem can be solved by first starting with a standard round robin schedule for 12 players. Split this into two equal parts to represent the two venues, next remove two of the rounds, and finally add back the removed matches as the 4th match at carefully chosen venues.  To get the schedule below I have started with a court balanced round robin and have made sure that the 4th matches have been added back to the same half of the schedule that they originally came from, this ensures venue balance where teams play 5 times at one venue and six times at the other.

Venue 1                        Venue 2
(C F)  (H L)  (I K)  (C L)     (D E)  (A J)  (B G)  (E J)
(G K)  (A I)  (H J)  (A G)     (F L)  (C D)  (B E)  
(A H)  (F J)  (G I)  (F H)     (E K)  (B C)  (D L)  (C K)
(G L)  (C E)  (B F)            (A D)  (I J)  (H K)  (D J)
(E F)  (B I)  (J L)  (E I)     (C H)  (D G)  (A K)  (G H)
(B D)  (A C)  (E L)  (A B)     (F K)  (H I)  (G J)  
(D I)  (B K)  (C J)  (D K)     (A L)  (F G)  (E H)  
(B J)  (E G)  (D H)            (C I)  (A F)  (K L)  (F I)
(J K)  (D F)  (C G)            (B H)  (I L)  (A E)  (B L)

Hope that helps.

Ian.