English Cricket League with 19 divisions. Some of the divisions (11) have 10 teams some (8) have 12 teams. The 10 team divisions have 18 matches, the 12 team divisions 22 matches, all play all twice. The 12 teams divisions playing an extra 4 weeks at the end
My problem is ground sharing.
I have tables which allow sharing between teams in the 12 team divisions and tables which work for the 10 team divisions, they have full flexibility and I only need 5 grounds to play 10 team divisions on or 6 grounds for the 12 team divisions so all the grounds get used every week. All has been fine for several years and I even have it so no one plays 3 consecutive home matches or 3 of 4 at home. Week 1 reverses to week 10 etc and although not totally necessary the teams don't want to play the same club on consecutive weeks
Now we want to have promotion and relegation such that a team in a 10 team division might share a ground with a team playing in a 12 team division. All matches play on a saturday and start at the same time so any teams sharing gounds must be arranged so those teams do not play at home on the same date.
I can make this work for the first 9 rounds, but when the 10 team division fixtures reverse it of course goes wrong. I can't just change the 12 team schedules to place rounds 10 and 11 at the end as they would then play the same teams on consecutive weeks which is a no no for them.
Any ideas ?