How about doing away with divisions? With 13 opponents and 8 league games, everybody would play everybody else 3 times in every 5-year period with one game left over. That game could be the "rivalry" game, so rivals play 4 times every 5 years. Still not perfectly fair, but a lot more fair than we have now. The top two in the conference play in the championship game. This may make it more likely that the championship game would be a rematch. That is probably not desirable. So you could say that if 1vs 2 would be a rematch, then play 1 vs 3 (unless that is also a rematch, then stick with 1 vs 2).