16 teams
top 5 rated conf champs get an auto bid but they must be top 25 or it opens an at large bid. that leaves at least 11 open.
the 11 open spots are at large though if auto-bids are given, they need to be based on conference standings, not human selection. I lean to at large bids but the selection criteria is all kinds of jacked up and needs to be fixed.
something has to happen with schedule parity, I think the sport wants marquee match ups and for this purpose yes that means Texas and Notre Dame, but it also means (this year) Tech and BYU playing Oregon or Tennessee, etc., etc. So to incentivize better scheduling there needs to be a way to rank teams based on schedule difficulty. I think rankings against top 16 teams should be weighted heavily and frankly maybe the most important factor. how you win should be ignored, how you lose should be ignored, and record should only be relevant to differentiate within a set of parameters focusing on how you performed against the play off teams.
With 16 teams, everyone in the playoffs will have at least 1 game against play off caliber teams, and frankly if OCC scheduling does what it should with this approach, every contender should have at least 2 if not more. then schedule parity is less of an issue as record against top competition becomes paramount.
What to do with conference championship games - I like them, that has to be solved for. Gruden's idea is interesting, maybe the round of 16 is conf championships and a play in for the round of 8 and you reseed at the round of 8. dunno, but being penalized with a game for the conf championship is odd.