This is the schedule for 11 or 12 players or teams. You could randomly select the two rounds that would
not be played each season. There are 39,916,800 (11!) ways to randomly assign the teams to pairing numbers, so I can't give you all of them. You can choose a few ways
here though.
11 or 12 players Rd Pairings
1: 1-12 7-6 11-2 8-5 10-3 9-4
2: 12-7 2-1 6-8 3-11 5-9 4-10
3: 2-12 8-7 1-3 9-6 11-4 10-5
4: 12-8 3-2 7-9 4-1 6-10 5-11
5: 3-12 9-8 2-4 10-7 1-5 11-6
6: 12-9 4-3 8-10 5-2 7-11 6-1
7: 4-12 10-9 3-5 11-8 2-6 1-7
8: 12-10 5-4 9-11 6-3 8-1 7-2
9: 5-12 11-10 4-6 1-9 3-7 2-8
10: 12-11 6-5 10-1 7-4 9-2 8-3
11: 6-12 1-11 5-7 2-10 4-8 3-9