Oklahoma, Clemson, Alabama and Ohio State. Teams like Michigan State, LSU, Georgia, FSU, will punch their way to a good season every 6-7 years. Look at the teams that have made it to the playoff:

LSU
Oklahoma (x4)
Clemson (x5)
Ohio State (x3)
Notre Dame
Michigan State
Alabama (x5)
Georgia
Washington
Oregon
Florida State

11 teams in six years. Other P5 teams have no shot. The Pac 12 champ has made it two times. Only one Big 12 team has made it. G5 teams have no shot.

The last six years of the BCS, 9 different teams made it, with half as many openings.