College football updated SP+ rankings after Week 12

On both television and Twitter on Saturday, we saw a pretty definitive shift in sentiment: Yes, Georgia still might be the best team in the country, but following an utterly ruthless performance against Michigan State, you might call Ohio State a co-No. 1 when it comes to current quality.

If you've been following SP+ from week to week this season, you know that it's been telling you that for a while. The Buckeyes briefly caught the Dawgs for the No. 1 spot a few weeks ago before dropping back to No. 2 following less-than-perfect performances against Penn State and Nebraska. But Saturday's brilliance pushed Ohio State back up the chart a bit -- UGA and OSU are now virtually tied atop the SP+ rankings, with Georgia sporting a 33.33 rating to Ohio State's 33.25. Georgia's No. 1 in defense, and Ohio State's No. 1 in both offense and special teams.

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.