We know one thing: Ohio State has earned the right to be called the best team in the country (on paper). Beyond that, Week 13 of the college football season only blurred the picture. The No. 2 (Alabama) and No. 4 (Ole Miss) teams in last week’s SP+ rankings both lost, No. 3 Texas looked lost offensively, and No. 7 Penn State thought hard about losing, too.

Ohio State expanded its lead in this week’s SP+ ratings to a comfortable degree, but we’ve now got a three-loss team at No. 2, and the second- and ninth-best teams are separated by only 3.5 points, barely more than the typical home-field advantage adjustment (2.5).

It’s getting messy out there! I love it! 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 both 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-looking. 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.

This week’s movers

Let’s take a look at the teams that saw the biggest change in their overall ratings. (Note: We’re looking at ratings, not rankings.)

Moving up

Here are the 10 teams that saw their ratings rise the most this week:

• Akron: up 3.8 adjusted points per game (ranking rose from 132nd to 125th)

• Bowling Green: up 3.7 points (from 75th to 63rd)

• UNLV: up 3.5 points (from 46th to 30th)

• Georgia Southern: up 3.3 points (from 98th to 83rd)

• New Mexico State: up 3.3 points (from 129th to 124th)

• UAB: up 3.2 points (from 118th to 106th)

• South Alabama: up 3.1 points (from 66th to 56th)

• Miami: up 2.9 points (from ninth to eighth)

• Tennessee: up 2.8 points (from 10th to ninth)

• Louisiana: up 2.8 points (from 47th to 34th)

As has been common for the last few weeks, most of the largest movement has come at the mid-major level. But SP+ always loves a nice, larger-than-expected blowout of a bad team and smiled on Tennessee’s performance in a 56-0 win over UTEP. And with Miami’s defense actually showing up against Wake Forest, the Hurricanes’ rating rose nicely, too.

Moving down

Here are the 10 teams whose ratings fell the most:

• UTEP: down 3.8 adjusted points per game (ranking fell from 127th to 131st)

• Rice: down 3.7 points (from 102nd to 110th)

• Northwestern: down 3.7 points (from 90th to 100th)

• Cincinnati: down 3.0 points (from 57th to 68th)

• Kent State: down 3.0 points (no change from 134th)

• Louisiana Tech: down 2.9 points (from 104th to 111th)

• Army: down 2.9 points (from 32nd to 45th)

• North Carolina: down 2.9 points (from 30th to 44th)

• Wisconsin: down 2.8 points (from 50th to 59th)

• Maryland: down 2.8 points (from 73rd to 84th)

Wisconsin started out 26th in the preseason, plummeted to 66th following a 2-2 start, charged all the way back to 20th with a run of blowouts and is now back to 59th after a couple of horrific road performances against Iowa and Nebraska. Even a strong home performance against Oregon could only stem the tide so much. What a strange year in Madison.

I should probably note one team whose rating really didn’t fall at all: Ole Miss. The Rebels suffered their third loss of the season Saturday against Florida, but they are still at No. 2. How? For starters, their blowouts of South Carolina and Georgia (relatively speaking) continue to look pretty awesome on paper, and the fact that they comfortably handled the Oklahoma team that just TKO’d Alabama helps, too.

But they were also the statistically superior team Saturday in Gainesville, producing a dramatically higher success rate (48% to 33%) and creating more red zone chances (three to two). It took a pretty unique combination of poor luck in turnovers and poor finishing in the red zone for them to lose that game; in fact, my postgame win expectancy measure — which takes all of the key predictive stats produced in a given game and says, “With these stats, you could have expected to win this game X% of the time” — says Ole Miss would have won this game 74% of the time by an average of 5.1 points.

With other top teams also disappointing to some degree, the Rebels’ rating didn’t really change despite the loss. Three losses by a combined 13 points might keep them out of the CFP, but that doesn’t mean they’re not an awesome team.

Conference rankings

Here are FBS’ 10 conferences, ranked by average SP+:

1. SEC: 14.8 average adjusted points per game (33.0 offense, 19.2 defense)

2. Big Ten: 6.6 average (26.9 offense, 20.5 defense)

3. ACC: 5.2 average (30.2 offense, 25.1 average)

4. Big 12: 4.5 average (29.7 offense, 25.4 defense)

5. Sun Belt: -6.4 average (25.3 offense, 31.7 defense)

6. AAC: -7.3 average (25.6 offense, 33.0 defense)

7. Mountain West: -8.2 average (24.3 offense, 31.6 defense)

8. MAC: -12.6 average (18.7 offense, 32.1 defense)

9. Conference USA: -13.8 average (18.7 offense, 32.1 defense)

With the middle and bottom of the Big Ten looking as poor as ever, the Big Ten slipped a bit in Week 13. Its average is now just 2.1 points ahead of the Big 12’s and 8.2 points behind the SEC’s. The SEC has certainly proven its depth this season, with upsets and near-upsets galore. What that should mean regarding the College Football Playoff, however, is in the eye of the beholder.

Résumé SP+

Since the College Football Playoff rankings are on the horizon, I’m also including Résumé SP+ rankings in this piece each week.

As mentioned above, SP+ is intended to be a power rating, not a résumé evaluation tool, but Résumé SP+ attempts to address this. It looks at two things: (1) how the average SP+ top-five team would be projected to perform against your schedule (in terms of scoring margin) and (2) how your scoring margin compares to (1). Throw in a seven-point penalty for every loss a team has suffered, and you can say that this is what the CFP rankings would look like if SP+ were in charge.

(Note: Because of the high bar teams have to clear in getting compared to an average top-five team, and because of the loss adjustment, almost every team here ends up with a negative score. It is what it is.)

Here is this week’s Résumé SP+ top 15:

1. Ohio State (10-1): -7.5
2. Texas (10-1): -7.8
3. Notre Dame (10-1): -9.9
4. Oregon (11-0): -10.8
5. Miami (10-1): -15.3
6. Indiana (10-1): -15.6
7. Penn State (10-1): -16.4
8. Georgia (9-2): -18.0
9. SMU (10-1): -19.7
10. Tennessee (9-2): -19.7
11. Ole Miss (8-3): -23.9
12. Boise State (10-1): -25.1
13. Alabama (8-3): -25.2
14. Tulane (9-2): -26.1
15. Clemson (9-2): -27.3

Even if you remove the loss adjustment, no one would have a positive résumé rating this season; that’s the first time I can remember that happening. Ohio State and Texas are coming awfully close, of course, and Oregon would be close if not for a couple of mediocre performances to start the season. Notre Dame has been consistently awesome since Week 2, when the Fighting Irish suffered the most damning loss of the season for any semi-elite team. It’s been a weird year. And unless Ohio State runs away with everything, we should be gearing up for a pretty weird postseason, too.