As is his wont, Hamilton approached the question quantitatively:
…if you do believe in such a thing as the (probabilistically) best team in the country, the more teams you put in the playoffs, the less likely it is that the best team ends up being declared the champion. Suppose for example that there’s a team that with 80% probability would win its game against any other team that might make the playoffs. With a single championship game, that superior team gets declared the champion with probability 80%. With a 4-team playoff, the best team must win both its games, the probability of which is (0.8)(0.8) = 0.64. With an 8-team playoff, the best team is only going to be declared the champion about half the time.
So a playoff system actually makes it less likely that the “best” team will be declared the national champion (assuming that the BCS chooses the best two teams for the title game, which is admittedly a weak assumption).
I would add another danger of the playoff system, which is that it makes championships weighted equally across years, despite the huge disparity in overall competition from year to year. For instance, no one would compare the 2005 BCS bowl game to the 2007 edition. The first featured undefeated USC, led by Heisman winners Reggie Bush and Matt Leinart, facing undefeated Texas, with the legendary Vince Young. Those were clearly two of the best teams of recent memory. The 2007 game had a one-loss Ohio State out of a weak Big-10 playing a two-loss LSU, and the contest wasn’t that good. I don’t see why those two titles should be counted equally, since the 2005 one is obviously better in almost every way. The BCS allows for easier comparisons between years like this, since the teams didn’t advance through the same system of playoffs.
Of course as important as football is, the larger point is that this is a discussion right now because Congress, unbelievably, is gearing up to legislate on the college football postseason. Hamilton writes,
But whatever you may think of the merits of a college football playoff, doesn’t it bother you to see the U.S. Congress acting as if it’s the nation’s ruler on this matter?
It does me. Which is why I wrote this.
You wonder where it ends. I thought I got a pretty raw deal when I was picked 11th for pickup basketball when I was in 8th grade. Is Congress going to look into that?