College football SP+ rankings after Week 10

If you've been following the SP+ rankings week-to-week this season, you've noticed how the tiers have taken shape of late: Georgia and Ohio State in some order, then a gap, then Alabama, then a big gap, then everyone else.

None of that changed after Week 10, but the gaps got a little more pronounced. Georgia hopped back ahead of Ohio State for the top spot, while the gap between the Dawgs and third-ranked Alabama expanded to more than four points. The gap between Bama and the rest of the field, though? Still huge. The Crimson Tide are 5.2 points ahead of the No. 4 team -- the same gap separating No. 4 and No. 13.

There was some shuffling among that No. 4-13 cluster, however. Let's take a look!

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.