The Lab CFB ratings movers, week 7: Ole Miss climbs 5 spots, and Ohio State is number 1 after Georgia and Alabama lose
CFB ratings movers, week 7: Ole Miss climbs 5 spots, and Ohio State is number 1 after Georgia and Alabama lose
After week 7, Ole Miss's 31 to 3 win over Missouri was the biggest rating gain in our college football rating, Georgia and Alabama both lost, and Colorado gained rating points in a loss. Each move below is traced to the game and the margin our number expected.
Georgia and Alabama both lost in week 7, and Ohio State is number 1 in our rating after winning 19 to 15 at Indiana. Georgia lost 27 to 24 at home to Auburn when our rating expected Georgia by about 18.5, and Alabama lost 26 to 10 at Tennessee when it expected Alabama by about 8.5. The biggest single gain belongs to Ole Miss, which beat Missouri 31 to 3 at home against an expected margin of about 2. Ole Miss gained 3.769 rating points and moved from 10th to 5th in our rating, while Missouri lost 3.517 and fell from 8th to 12th. Army had the largest climb, 69th to 48th, and Temple the largest drop, 93rd to 110th.
Every rating, rank, move and expected margin here is from our in-season CFB rating, the weekly update layer on top of each team’s preseason number, and every score is from the game results. The week 7 rows were written after Saturday’s finals, and each team’s entering rating below equals its week 6 row. “Rank” always means rank in our rating across the 138 FBS teams we rate, not any poll. Figures are rounded from stored values. A rating and its move are each rounded to three decimals on their own, so a week 6 rating plus its move can miss the week 7 rating by 0.001.
How a move is computed
Each team’s rating moves by one number: a weight times its error. The error is the game’s margin, capped at 28, minus the margin our ratings expected. The expected margin is the team’s rating minus its opponent’s, plus 2.5 points for home field and nothing at a neutral site. The weight shrinks as the season goes on.
Worked example, Ole Miss at home against Missouri:
- Expected margin: Ole Miss’s entering rating of 16.040 minus Missouri’s 16.920 is minus 0.880. Ole Miss was at home, so add 2.5, for plus 1.62. Our rating had Ole Miss winning by about 2.
- Actual margin: Ole Miss 31, Missouri 3, so plus 28. That is right at the cap, so it counts in full.
- Error: 28 minus 1.62 is 26.38.
- Weight: a team’s sixth game, with five already played, carries a weight of 2/14, or 0.1429.
- Move: 26.38 times 2/14 is 3.769 rating points.
Missouri, on the other side of the same game, was playing its seventh game, with six already played, so its weight was 2/15. Its error was minus 26.38, and 26.38 times 2/15 is a loss of 3.517, not 3.769.
That weight comes from setting the preseason prior to be worth about eight games of evidence. We walk through that choice in the preseason prior is worth eight games. Two consequences matter for this week. Each team’s weight depends on how many games it has already played: 53 teams in their sixth game carried 2/14, 67 in their seventh carried 2/15, and Eastern Michigan, in its eighth, carried 2/16. And nothing past 28 points counts, even when the opponent was supposed to be much worse.
Why a loss can raise a rating
Colorado is the clean case. It lost 27 to 24 at home to Utah, a margin of -3, and its rating went up 2.368. Our rating expected Utah to win by about 19.6: Colorado’s entering minus 6.121 minus Utah’s 15.957 is minus 22.078, and Colorado’s home field takes it to minus 19.578. The error is minus 3 minus minus 19.578, which is 16.578, and 2/14 of that is +2.368. Colorado moved from 98th to 85th, from a rating of minus 6.121 to minus 3.752. Utah, with the same weight, lost the same 2.368 for the win and stayed 11th.
It was not the only one. Oklahoma State lost 35 to 32 at Houston and gained 1.073, and Michigan State lost 24 to 21 to Northwestern and gained 0.979. Northwestern’s road win cost it 1.049 and dropped it from 22nd to 31st. Across the week, 12 teams lost and still gained rating points, and 14 won and lost them. Two of those 14, Clemson and Texas A&M, beat FCS opponents, which we pin at minus 22, by 37 and 41 points against expected margins of about 29 and 36.
None of that is a verdict on the games. With Utah expected by 19.6, a 3 point loss at home beat the expectation by 16.6 points, and beating the expectation is what moves the number up.
Biggest risers
Margin and expected margin are from the team’s side. “Site” is home or road for the risers and fallers, taken from the game results.
| Team | Our rank, wk 6 to wk 7 | Rating change | Opponent | Site | Margin | Expected |
|---|---|---|---|---|---|---|
| Ole Miss | 10 to 5 | +3.769 | Missouri | Home | +28 | +1.62 |
| Army | 69 to 48 | +3.565 | Florida Atlantic | Home | +32 (counts as 28) | +3.04 |
| Charlotte | 137 to 133 | +3.342 | Temple | Road | +7 | -18.06 |
| Tennessee | 12 to 8 | +3.264 | Alabama | Home | +16 | -8.48 |
| Tulsa | 107 to 91 | +3.228 | Rice | Road | +21 | -3.21 |
| Auburn | 28 to 15 | +3.071 | Georgia | Road | +3 | -18.50 |
| TCU | 51 to 42 | +2.855 | Baylor | Road | +11 | -8.98 |
| Louisiana | 71 to 54 | +2.717 | Troy | Home | +27 | +6.62 |
Auburn’s 3 point win at Georgia came when our rating expected Georgia by 18.5, a 21.5 point miss, and moved Auburn up 13 spots. Charlotte won at Temple by 7 when it expected Temple by about 18, a 25 point miss, and Charlotte is still 133rd of 138. Army’s 56 to 24 win over Florida Atlantic was by 32, but the part past 28 did not count.
Biggest fallers
Every faller is the other side of a riser’s game.
| Team | Our rank, wk 6 to wk 7 | Rating change | Opponent | Site | Margin | Expected |
|---|---|---|---|---|---|---|
| Florida Atlantic | 74 to 89 | -3.565 | Army | Road | -32 (counts as -28) | -3.04 |
| Missouri | 8 to 12 | -3.517 | Ole Miss | Road | -28 | -1.62 |
| Temple | 93 to 110 | -3.342 | Charlotte | Home | -7 | +18.06 |
| Alabama | 2 to 3 | -3.264 | Tennessee | Road | -16 | +8.48 |
| Rice | 103 to 118 | -3.228 | Tulsa | Home | -21 | +3.21 |
| Troy | 94 to 107 | -2.911 | Louisiana | Road | -27 | -6.62 |
| Georgia | 1 to 2 | -2.866 | Auburn | Home | -3 | +18.50 |
| Baylor | 32 to 38 | -2.855 | TCU | Home | -11 | +8.98 |
Each game pairs the two teams, but each side moves by its own weight, so the two moves match only when both teams have played the same number of games. Three of these eight pairs do not match. Ole Miss gained 3.769 at 2/14 while Missouri lost 3.517 at 2/15. Auburn gained 3.071 at 2/14 while Georgia lost 2.866 at 2/15. Louisiana gained 2.717 at 2/15 while Troy lost 2.911 at 2/14. In each case the heavier weight went to the team with fewer games played.
The top 10 after week 7
Ohio State is number 1 in our rating, at 23.896, and it got there on a 4 point win that lowered its rating. Ohio State won 19 to 15 at Indiana against an expected margin of 4.67: its entering 23.985 minus Indiana’s 16.812 is 7.173, and Indiana’s home field takes it to 4.673. A 4 point win against that expectation cost 0.090, so Ohio State moved from 23.985 to 23.896 and from 3rd to 1st. Georgia fell 2.866 to 22.977 and is second, 0.919 behind. Alabama fell 3.264 to 21.943 and is third.
| Rank | Team | Rating | Change from week 6 | Rank last week |
|---|---|---|---|---|
| 1 | Ohio State | 23.896 | -0.090 | 3 |
| 2 | Georgia | 22.977 | -2.866 | 1 |
| 3 | Alabama | 21.943 | -3.264 | 2 |
| 4 | LSU | 20.303 | +2.253 | 7 |
| 5 | Ole Miss | 19.808 | +3.769 | 10 |
| 6 | Miami | 19.325 | -1.044 | 5 |
| 7 | Notre Dame | 19.193 | -1.353 | 4 |
| 8 | Tennessee | 17.494 | +3.264 | 12 |
| 9 | Texas | 17.285 | -2.417 | 6 |
| 10 | Indiana | 16.902 | +0.090 | 9 |
LSU rose from 7th to 4th with a 31 to 0 win over Mississippi State, against an expected margin of 11.10. The margin counted as 28, so the error was 16.9, and 2/15 of that is a gain of 2.253. Notre Dame fell from 4th to 7th after a 28 to 24 loss at BYU, when our rating expected Notre Dame by 6.15, and lost 1.353. Texas dropped from 6th to 9th after a 27 to 24 loss at home to Florida against an expected margin of 13.92. Miami won 43 to 35 over Florida State and lost 1.044, because our rating expected Miami by 15.3, which moved it from 5th to 6th. In all, 17 teams were idle in week 7, and none of them was in the top 10.
Next week
25 of the 138 teams moved 10 or more spots in our rating this week, and 1 moved 20 or more, Army at 21 spots. Week 8 has two games between teams in our top 20: Ole Miss at Texas, our 5th and 9th, and LSU at Auburn, our 4th and 15th. The full board, updated after each week’s finals, is on our college football power ratings page.