College football SP+ rankings after Week 9

Heading into November, college football's hierarchy is pretty well-established: Defense-driven Georgia and offense-driven Ohio State are the teams playing at the highest overall level, Alabama rounds out the top three ... and there's a chasm separating those three from everyone else.

Both the Buckeyes and Crimson Tide have suffered losses this season and could be one more upset away from elimination in the College Football Playoff race. But a predictive system like SP+ trusts them far more than the rest of the field.

In the updated SP+ ratings, Ohio State and Georgia are 3.1 and 2.4 points ahead of Bama, respectively, and Bama is at least 3.8 points ahead of everyone else. Early-season upsets could create some late-season drama, but when it comes to projected level of play moving forward, we know who the top teams are.

What is SP+? In a single sentence, it's a tempo- and opponent-adjusted measure of college football efficiency. I created the system at Football Outsiders in 2008, and as my experience with both college football and its stats has grown, I have made quite a few tweaks to the system.

It is, as always, important to note that SP+ is intended to be predictive and forward-facing. It is not a résumé ranking that gives credit for big wins or particularly brave scheduling -- no good predictive system is. It is simply a measure of the most sustainable and predictable aspects of football. If you're lucky or unimpressive in a win, your rating will probably fall. If you're strong and unlucky in a loss, it will probably rise. It is a look at how teams should likely perform moving forward.