Just when Ohio State eased ahead in the "Who's the best team in college football?" conversation, Rivalry Week reeled the Buckeyes right back in. Saturday's loss to Michigan both knocked them out of the Big Ten title race and once again compressed the top of the SP+ ratings. The top four teams are all within two points of each other, and the top 10 are all within five and a half. This is pretty much exactly what you want to see heading into the first 12-team CFP.
Here's another thing you want to see: tightly projected conference championship games. Based on the ratings below, eight of nine title games are projected within 5.4 points, including all four power-conference games: Georgia vs. Texas (Horns by 1.5), Oregon vs. Penn State (Ducks by 3.2), Iowa State vs. Arizona State (Cyclones by 3.7, though SP+ has been underselling ASU for a while) and SMU vs. Clemson (Mustangs by 5.4).
Below are this week's SP+ rankings. 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 college football and its stats has grown, I have made quite a few tweaks to the system.
SP+ is indeed intended to be predictive and forward-facing. It is not a résumé ranking, so it does not automatically give credit for big wins or particularly brave scheduling -- no good predictive system does. 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.