I think eight is ideal, all five P5 conference champ, the highest ranked non P5 champion, plus two at large.
77 nailed it. i also like first round at home.
5 p5 conf champs, 1 from non p5 if ranked in top 12 or 15, then two w/cards. this year it wud hv added wiscy, ucf and alabama to conf champs mutts, clempson, USC, Okla and Buckeyes. interesting notes: 1, USC gets in? 2, wispy-ohio st conf championship game becomes semi-meaningless if both get in? 3, seeding would become interesting. (in my mind, seed two from same conf in same bracket half and then you never have to worry about two from same conf in championship game, unless they're in top 4..this year they were so we're stuck.)
i experiment w/this every year and this year would have looked
1 clemp
8 UCF
4 alabama
5 ohiost
2 georgia
7 USC
3 oklahoma
6 Wisc
barring an upset, looks like nothing would have changed w/eight team playoff....but the ncaa would have gotten a bunch more cash.