As one might expect, considering many of college football's top teams either took a bye or played an FCS team on Saturday, there wasn't much movement atop this week's SP+ ratings. Minnesota beat Bye well enough to hop Auburn and Michigan by decimal points to 10th, and that was about it. Last week's rankings are, for the most part, this week's.

There was still some interesting movement beneath the surface, though.

* Navy thumped UConn worse than most teams have, and the Midshipmen moved from 39th to 31st. They are one of SIX AAC teams in the top 40, and the AAC West's average rating (plus-6.5 adjusted points per game) now ranks ahead of three power conference divisions: the Pac-12 South (6.2), the ACC Atlantic (5.2), and the lowly ACC Coastal (2.8). If UConn had left the league this year instead of next, the AAC would actually rate better than the ACC overall. What a year it's been for both conferences (in completely different ways).

* Oregon State's thumping of Arizona moved the Beavers to 4-4 overall and 59th in SP+. They were 111th last year. We probably haven't talked enough about the job Jonathan Smith has done in Corvallis this year.

* Northwestern's horrid showing at Indiana dropped the Wildcats from 76th to 94th. The defense has slipped to a merely good 21st, and the offense is 126th, easily the worst of the often offensively challenged Pat Fitzgerald era.

* Syracuse got wrecked by Boston College at home on Saturday, dropping the Orange -- 10-3 just a year ago -- to 3-6 and 92nd overall. The offense has been sketchy all year (it's currently 99th), but the defense has been far leakier than expected, too (69th). Bad year up north.

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. SP+ is intended to be predictive and forward-facing. That is important to remember. 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.