If you really want to make the regular season matter, which I have always believed is something college football has over pro, than requiring playoff teams to be conference champions is a great idea. That way teams have to fight and claw to win their division, and then conference championship games because they know that they can still have a chance if others lose their conference championship game.
If you have to win your conference and for almost all conferences that means your conference championship game, than instead of a 4 team playoff we have roughly a 6-10+ team playoff with conference championship games serving as quarterfinals.
From last year here are 7 games that would have mattered huge. You would have had to watch every game to see how the playoff picture would unfold. In at least 3 of the games whoever won would have made the playoff. In other words, those were quarter-final games.
1 LSU vs 9 South Carolina
This game is simple, winner represents the SEC in the playoff because both teams are ranked high enough.
3 Oklahoma State vs 14 OU | 8 Kansas State vs Someone
This Big 12 should go back to a CCG, that way we could have had OSU vs KSU; winner gets a spot in the playoff. As it worked out it would have been OSU if they won or a 3 way tie if they lost.
5 Oregon vs UCLA 7-9 USC (obviously it was UCLA)
If USC was playing in this game (and they will be this year) than this game is simple as well; winner represents the PAC 12 in the playoff.
7 Boise State vs New Mexico
If Boise were part of the playoff than they would have to win their last game to make the playoffs. Their road in the Big East will be tougher going forward.
10 Wisconsin vs. 17 Michigan State
The B1G wouldn’t have a representative in the playoffs if Wisconsin won unless Boise lost or Wisconsin jumped over one of the other teams.
11 Virginia Tech vs 15 Clemson
By winning Virginia Tech would make a playoff if Boise and Wisconsin lost OR they jumped 1 or 2 teams.
You probably would never get the 4 "best" teams, and upsets do happen. BUT you would make the regular season and conference championship games much more compelling and would essentially have quarterfinals (plus others games that mattered on the first Saturday of December).
The implications of this would be far reaching for a lot of teams. Nebraska for instance, sitting at 7-1 or 8-2 would not only have a chance to still win its division, but the NATIONAL CHAMPIONSHIP. If you win your division and then CCG you had a decent
This means that late into the season, say after week 8 or 9, 15-20 teams could still have a legitimate hope for the national championship.