those CFP contenders that aren't playing in a Conference Championship Game.

This is also an easy way to expand the CFP without really affecting the current structure or schedule.

During CCG weekend - and before the final CFP rankings - imagine a bunch of games like:

BYU v. Notre Dame
Ole Miss v. Ohio State
Miami v. Tennessee
Alabama v. Indiana

They don't even need to be strictly 'play-in' games - just a 13th game and 13th data point to put all CFP contenders on similar footing. For instance, BYU and Ole Miss wins over Notre Dame and Ohio State significantly help BYU's and Ole Miss' playoff resumes, but don't necessarily knock out Notre Dame and Ohio State - and don't necessarily push BYU or Ole Miss into the CFP....but most likely knock out SMU.