Alright, had to cross a couple more Ts, dot a couple more Is, etc., but it’s time to get rolling with the S&P+ updates. You can now find full, updated 2005 S&P+ rankings at Football Outsiders — overall, offense, defense.
What changes have I made?
I’ll include this blurb in each of these posts.
First, with a better chance to analyze which statistical factors are most consistent from the beginning of the season to the end, I made some slight tweaks in the weighting of each statistical factor (the short version: efficiency carries even more weight now). I also worked marginal efficiency and marginal explosiveness into the equation.
Then, I implemented the changes I made during 2018 for previous years. From each week’s rankings post:
- I changed the garbage time definition. S&P+ stops counting the major stats once the game has entered garbage time. Previously, that was when a game ceased to be within 27 points in the first quarter, 24 in the second, 21 in the third, and 16 in the fourth. Now I have expanded it: garbage time adjustments don’t begin until a game is outside of 43 points in the first quarter, 37 in the second, 27 in the third, and 21 in the fourth. That change came because of a piece I wrote about game states at Football Study Hall.
- Preseason projections will remain in the formulas all season. Fans hate this — it’s the biggest complaint I’ve heard regarding ESPN’s FPI formulas. Instinctively, I hate it, too. But here’s the thing: it makes projections more accurate. Our sample size for determining quality in a given season is tiny, and incorporating projection factors found in the preseason rankings decreases the overall error in projections. (For previous years, from before I actually released any sort of preseason projections, I found the most predictive success by keeping a layer of five-year history within the ratings. It’s a small percentage, but it’s in there.)
- To counteract this conservative change, I’m also making S&P+ more reactive to results, especially early in the season. If I’m admitting that S&P+ needs previous-year performances to make it better, I’m also going to admit that S&P+ doesn’t know everything it needs to early in a season, and it’s going to react a bit more to actual results. Basically, I’ve added a step to the the rankings process: after the rankings are determined, I go back and project previous games based on those ratings, and I adjust the ratings based on how much the ratings fit (or don’t fit) those results. The adjustment isn’t enormous, and it diminishes dramatically as the season unfolds.
One more recent change had the most impact, however: I made S&P+ more reactive to conferences as well. It’s similar to step 3: after the rankings are determined, I project previous games based on those ratings, and I track each conference’s average performance versus projection. For the top conference, I found that by the end of the season it was aiming low by two or three points per game per team. For the bottom conference, it was the reverse.
By shifting each team’s rating based on this conference average, and by increasing the weight of said adjustment as the season progresses, it adds basically improves against-the-spread improvement by about one percent per season and cuts the average absolute error by somewhere between 0.2 and 0.3 points per game. That doesn’t seem like much, but look at the Prediction Tracker results and note how much of a difference 1% and 0.3 points per game could make to your projective ranking there. It’s pretty big.
It does, however, mean a fundamental shift in how mid-major teams are judged. Not to spoil the suspense, but look at the difference this adjustment made in some 2018 rankings:
- Fresno State: originally ninth, now 16th
- UCF: originally eighth, now 18th
- Utah State: originally 19th, now 21st
- Appalachian State: originally 11th, now 29th
It’s a pretty harsh adjustment, though it both makes the numbers better and perhaps passes the eye test a bit more. So we’re going with it.
Here are the basics:
2005 S&P+ rankings
|San Diego State||5-7||-2.4||72||26.7||63||29.1||74|
|San Jose State||3-8||-14.7||97||18.6||95||33.3||93|
|New Mexico State||0-12||-29.2||119||12.8||111||42.0||119|
These changes resulted in some pretty significant shifts.
- Teams that saw their rankings rise by 20 or more places from old method to new method: California (up 38 spots to 17th), Kansas State (up 28 to 47th), UConn (up 24 spots to 62nd), Washington State (up 23 spots to 23rd), UTEP (up 23 spots to 55th), Texas Tech (up 22 spots to seventh), Iowa State (up 20 spots to 22nd), Toledo (up 20 spots to 40th). Pac-12 and Big 12 teams appeared to get a nice boost.
- Teams that saw their rankings sink by 20 or more places: Army (down 31 spots to 101st), CMU (down 29 to 88th), USF (down 29 to 56th), Florida (down 27 to 45th!), Tulsa (down 26 to 60th), Southern Miss (down 24 to 64th), Florida State (down 23 to 51st), Memphis (down 22 to 75th). S&P+ hates the state of Florida, apparently.
Maybe the most noteworthy shift: Texas and USC switched places. The national champ is No. 1 now.
Want proof that 2005 was a long time ago? Here are your average S&P+ rankings by conference:
- Big Ten (plus-13.2)
- Big 12 (plus-12.1)
- Pac-10 (plus-11.1)
- ACC (plus-7.7)
- SEC (plus-7.6)
- Big East (plus-3.7)
- Mountain West (minus-0.8)
- Conference USA (minus-6.2)
- MAC (minus-10.0)
- WAC (minus-10.4)
- Sun Belt (minus-20.7)
The main tables at FO now include SOS rankings, and six of the top eight schedules belonged to the Big Ten. The SEC: only two of the top 30.
Offense wins championships
USC’s offense ranked No. 1 at 51.6 adjusted points per game. The Trojans were about as far ahead of No. 3 Arizona State (42.4) as ASU was of No. 31 Miami (33.0). The only team within nine points of USC’s offense: Texas, of course. And the Longhorns had a defense that was nearly five points per game better than USC’s, which tipped the S&P+ balance.
The U could play D
After winning 11 or more games every year from 2000-03, winning one national title and damn near winning another, Miami began to slip a bit in 2004. The 2005 season began with a 10-7 loss to FSU and ended with an embarrassing 40-3 Peach Bowl loss to LSU. (Larry Coker was gone after a 7-6 campaign in 2006.)
For all of the Canes’ offensive inconsistency, though, they could still defend. Only once in the regular season did they allow more than 17 points. They finish No. 1 in Def. S&P+, 1.3 points ahead of second-place Alabama and 3.9 points ahead of No. 5 Ohio State.
Ohio State and Texas, meanwhile, are the only two teams to finish with top-10 offenses and top-10 defenses. Six of the teams with top-10 defenses also had offenses that ranked 30th or worse.