I was listening to that. He argued with Maisel and Forde about it, too. He kept saying how momentum was very big in his decisions. I guess that means the most recent 5 years is more important than the first 5 years. That's why teams like Tennessee, Florida State, and Miami are lower than other people might have thought, and LSU is higher than other people thought (he used bowl wins over Miami and Notre Dame as his "momentum" examples).
That's all fine and whatever. But he didn't use the same thing to rate USC. He said that USC was not number one because in those first five years they were not very good in a not very good conference. So... basically, momentum is just a word he's using to put his list the way he wants it.
He said today that he got a lot of people whining about the list in emails. He made a good point (one of very few good points he makes): it's just a stupid list. Who cares? Feel free to make your own list.