Week 5 of the 2019 college football season featured some particularly dominant performances, not to mention a couple of surprisingly close calls. That, plus the continued phasing out of preseason projections and phasing in of opponent adjustments, meants quite a bit of movement at the top of this week's SP+ rankings.
Alabama still tops the list, but barely. Ohio State's continued ascent brought the Buckeyes to within 0.3 adjusted points per game of the top spot. Oklahoma's first-round knockout of Texas Tech -- the Sooners were up 17-0 after what seemed like 45 seconds -- bumped Lincoln Riley's squad from sixth to third, as well.
A couple of noteworthy teams fell a few spots, too. After needing a stop on a late two-point conversion attempt to beat UNC, defending national champion Clemson fell from third to sixth. And a week after embarrassing Michigan, Wisconsin needed defensive scores to survive an upset bid by a Northwestern team that had been inept for most of September.
Since SP+ is not a résumé rating, it is not required to reward teams for winning and punish teams for losing (just as it is not required to put Clemson in the No. 1 spot just because it is the defending champ). That said, this week's ratings are strangely symmetrical: the top 10 teams are all unbeaten, and 11 of the next 12 have one loss. It's not usually that clean a picture.
One last note: the gap among conferences is closing. I mean that in two different ways. First, though the SEC still grades out as the best conference in terms of average SP+ rating (it has a 13.0), its advantage over the Big 12 (12.6) and Big Ten (11.6) is shrinking quickly.
Second, the ACC is just having a miserable time of it at the moment. It has only two top-40 teams, and its average rating (4.0) is quite a bit closer to the AAC's (1.5) than the fourth-best of the power conferences, the Pac-12 (9.2). While the AAC would use this to bolster its "Power 6" claims, you could make the case that it's more like a Power 4 at the moment.
Note: 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.