College football is two things at once. At the top, it is as stolid and inflexible as it has been since the 1970s. Alabama, Clemson, Ohio State and Oklahoma have each finished in the AP top 10 for at least six straight years (Bama is at 13 straight) and have hogged 20 of 28 College Football Playoff bids. Plus, Georgia is at four straight top-10 finishes, and Notre Dame has been to two of the past three CFPs. We have a clear idea of who is in this sport's on-field ruling class.
Beneath the surface, however, it remains as chaotic as ever.
On average in the FBS, about 2.2 teams per season either improve or regress by at least 20 adjusted points per game in my SP+ ratings -- an extreme jump or stumble -- while a total of 27.5 per year move by at least 10 points.
Baylor has gone from 7-6 and 67th in SP+, to 11-3 and 18th, to 2-7 and 63rd in the past three years. Central Michigan went from 8-5 to 1-11 to 8-6 from 2017 to 2019. A lot of programs don't like standing still.
Typically, there's a rubber band effect. Of the teams that regressed by at least 10 adjusted points per game from 2005 to 2019, 66% improved the next season with an average change of plus-3.7 PPG; of the teams that improved by at least 10 adjusted PPG, 60% regressed the next year with an average change of minus-2.3. Even in a pandemic year, these trends mostly held. With practice and contact limitations, it was a difficult time to attempt a huge rebound, but schools like Nevada, Arkansas, Toledo, NC State, etc., pulled it off to varying degrees.
The 2021 season is approaching quickly, and we can be guaranteed a brand new set of twists and turns. But let's talk about the teams that made particularly strong moves, up or down, in the scattershot 2020 season. Of those that stumbled, which are the most likely to rebound quickly? Of those that surged, which are most likely to sustain their gains?