Four top-10 teams -- and nine ranked teams in all -- lost in Week 5 of the 2021 college football season, and the wackiness and chaos levels are higher than they've been in years. As you would expect, Week 5's unpredictability has resulted in a lot of movement in the SP+ ratings. However, the top three remain the same: Georgia, Alabama, and a rapidly improving Ohio State lead the way, a few steps ahead of everyone else.
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.
As we work our way into October, conference-level adjustments -- in which I look at how much initial SP+ ratings are missing on average for teams from given conferences and adjust accordingly (kind of like how house prices are determined in part by the neighborhood in which you live) -- begin to kick in a lot stronger. What does that mean for Week 5? Very good things for the Big Ten, which saw its teams receive healthy adjustments thanks to quality performance against projections.
Three Big Ten ratings are perhaps most noteworthy.
No. 3 Ohio State. The Buckeyes have beaten their last two opponents by a combined 111-20 and seem to be finding their defensive rhythm. Granted, walloping Akron and Rutgers doesn't tell us everything we need to know, but it was impressive, and combined with the Big Ten's friendly adjustments, Ohio State damn near caught Alabama for No. 2.
No. 10 Wisconsin. SP+ just can't quit the Badgers, who have now lost two games to higher-ranked Big Ten teams (Penn State by a small margin, Michigan by a larger one) and suffered a fluky loss to Notre Dame in which the Irish scored a kickoff return TD and two pick-sixes. It isn't sold on their faulty offense, obviously, but the defense has been so good that, again with help from the Big Ten adjustment, they remain more highly ranked than the eyeballs suggest they should.
No. 22 Nebraska. SP+ remained higher on the Huskers than most despite their 2-3 start, but they charged into the top 25 following their 56-7 humiliation of Northwestern on Saturday. They have obvious issues in close games, and have for most of Scott Frost's tenure, but play for play and drive for drive, they have been awfully good this year.
Biggest rises
Twelve teams rose by at least 10 spots this week.
Nebraska: up 25 spots from 47th to 22nd
Fresno State: up 18 spots from 59th to 41st
Minnesota: up 17 spots from 56th to 39th
Iowa: up 13 spots from 28th to 15th
Tennessee: up 13 spots from 32nd to 19th
South Carolina: up 13 spots from 86th to 73rd
FAU: up 13 spots from 88th to 75th
Virginia: up 11 spots from 58th to 47th
Florida State: up 10 spots from 73rd to 63rd
Houston: up 10 spots from 75th to 65th
Air Force: up 10 spots from 76th to 66th
Ball State: up 10 spots from 118th to 108th
The top of this list has a Big Ten flavor for the reasons mentioned above, but Fresno State jumped up despite a loss to Hawaii late on Saturday night. Why? First, with each game you play, your preseason projections carry less weight in the SP+ formula, so the Bulldogs' impressive early-season performances carried more weight this week and boosted them a bit. Second, SP+ viewed the loss to Hawaii as a pretty fluky occurrence. The Bulldogs outgained the Rainbow Warriors by 157 yards and 1.9 yards per play but suffered an unsustainable minus-5 turnover margin. It still trusts Fresno a good amount.
Biggest stumbles
Thirteen teams dropped by at least 11 spots
UCLA: down 22 spots from 10th to 32nd
SMU: down 15 spots from 40th to 55th
Missouri: down 15 spots from 52nd to 67th
Army: down 15 spots from 64th to 79th
Oregon: down 14 spots from 17th to 31st
Oregon State: down 14 spots from 43rd to 57th
California: down 14 spots from 67th to 81st
UAB: down 13 spots from 55th to 68th
Troy: down 13 spots from 74th to 87th
Arkansas: down 12 spots from 16th to 28th
Washington: down 11 spots from 38th to 49th
Tulane: down 11 spots from 77th to 88th
Colorado: down 11 spots from 94th to 105th
The presence of six Pac-12 teams on this list should pretty definitively tell you which conference suffered the most from the increased weight of conference-level adjustments.
