Writers of Pro Football Prospectus 2008

26 Oct 2011

FEI: Ordinary Drives

by Brian Fremeau

I didn’t exactly predict Wisconsin’s tumble last week from the ranks of the unbeatens, but the Badgers’ ridiculous offensive efficiency did take a bit of a tumble this week. After posting "only" 31 points against Michigan State’s terrific defense, Wisconsin’s raw offensive efficiency rating dropped by 25 percent. Of course, that still leaves the Badgers as the most efficient offense in the nation. Due to playing a top defense for the first time, their opponent-adjusted OFEI rating actually moved up from No. 12 to No. 6.

The Stanford Cardinal are hot on their heels in terms of raw efficiency (No. 3), but have yet to play a solid defense (No. 120 offensive strength of schedule to date) and may not face an elite opposing defense all year. Stanford backs up its offensive performance with one of the nation’s stingiest defenses, one that has a reasonably strong defensive SOS (No. 22). Those units will get tested by a competent all-around opponent in USC this weekend. But Stanford’s per-possession data on both sides of the ball is impressive:

  • No. 2 in offensive points per drive (4.2), No. 2 in defensive points per drive (0.9), and No. 2 in margin (3.3)
  • No. 25 in offensive points per explosive drive (6.9), No. 5 in defensive points per explosive drive (4.0) , and No. 1 in margin (2.9)
  • No. 15 in offensive points per methodical drive (5.0), No. 1 in defensive points per methodical drive (1.0), and No. 1 in margin (1.0)
  • No. 24 in offensive points per value drive (5.5), No. 1 in defensive points per value drive (2.7), and No. 1 in margin (2.8)

I was thinking about the correlation between explosive and methodical drives this weekend with success. As noted last week, there is a pretty strong relationship between these metrics and overall offensive efficiency, as would be expected. But how much scoring occurs on these special drives and how much occurs on "ordinary" drives? Explosive and Methodical drives are mutually exclusive drive types (since only 99 yards can be traversed by an offense, a possession cannot both average 10 yards per play and last at least 10 plays). But what about the rest?

I’m dubbing these possessions "Ordinary Drives", drives that do not last at least 10 plays and do not average at least 10 yards per play. As expected, teams don’t score as well on Ordinary Drives as they do on Explosive and Methodical drives. But how many points are scored in ordinary fashion?

It isn’t a good thing to play a lot of ordinary drives. 97 percent of Kent State’s offensive possessions are ordinary drives and they rank dead last nationally in offensive efficiency. Most of the top offenses also play the lowest percentage of ordinary drives. Only 54 percent of Wisconsin’s possession are ordinary drives, the lowest rate in the nation.

On average, teams score approximately 2.1 points per possession. On ordinary drives, the national average is 1.7 points per possession. The Stanford Cardinal rank first in offensive points per ordinary drive (3.0). Alabama tops all others defensively, holding opponents to 0.1 points per opponent ordinary drive. Michigan State’s defense forces the highest percentage of opponent ordinary drives (89.7 percent).

I haven’t added ordinary drives to the Offensive and Defensive splits charts yet because I’m interested in generating some feedback on it first. What efficiency metrics would you like to see regarding Ordinary, Explosive, Methodical and Value Drives? One longer-term concept would be to run field position adjusted efficiency data on each of these categories rather than sticking simply with points scored per drive, but if you have any other ideas, please share them in the comments section.

FEI Week 8 Top 25

The Fremeau Efficiency Index (FEI) rewards playing well against good teams, win or lose, and punishes losing to poor teams more harshly than it rewards defeating poor teams. FEI is drive-based, not play-by-play based, and it is specifically engineered to measure the college game.

FEI is the opponent-adjusted value of Game Efficiency (GE), a measurement of the success rate of a team scoring and preventing opponent scoring throughout the non-garbage-time possessions of a game. FEI represents a team's efficiency value over average. Strength of Schedule (SOS) is calculated as the likelihood that an "elite team" (two standard deviations above average) would win every game on the given team's schedule. "SOS Pvs" represents only games played to date. "SOS Fut" represents only remaining scheduled games.

Mean Wins (FBS MW) represent the average total games a team with the given FEI rating should expect to win against its complete schedule of FBS opponents. Remaining Mean Wins (FBS RMW) represent the average expected team wins for games scheduled but not yet played.

Offensive FEI (OFEI), Defensive FEI (DFEI), Special Teams Efficiency (STE) are also provided, along with Field Position Advantage (FPA), the share of the value of total starting field position earned by each team against its opponents.

Only games between FBS teams are considered in the FEI calculations. These FEI ratings are a function of results of games played through October 22. The ratings for all FBS teams can be found here. You can also find OFEI, DFEI, and STE on their own pages.

Rk Team FBS
W-L
FEI Last
Wk
GE GE
Rk
SOS
Pvs
Rk SOS
Fut
Rk FBS
MW
FBS
RW
OFEI Rk DFEI Rk STE Rk FPA Rk
1 LSU 7-0 .312 1 .306 5 .430 54 .355 15 9.7 3.3 .385 19 -.743 3 4.779 1 .615 2
2 Alabama 8-0 .269 2 .392 3 .498 69 .399 30 9.5 2.2 .522 13 -.499 15 .680 42 .554 11
3 Clemson 7-0 .248 7 .200 13 .502 72 .534 55 9.4 3.2 .555 8 -.440 17 1.959 22 .535 22
4 Oklahoma State 7-0 .246 10 .250 8 .406 45 .386 26 9.9 3.9 .185 41 -.709 4 1.668 25 .554 10
5 Michigan State 5-1 .245 11 .147 18 .306 22 .644 67 9.1 4.4 .305 25 -.697 5 1.718 24 .526 33
6 Boise State 7-0 .237 5 .311 4 .535 80 .871 96 11.0 4.8 .205 37 -.631 7 2.776 12 .616 1
7 Stanford 7-0 .235 9 .438 2 .863 117 .386 27 10.6 3.9 .187 39 -.65 6 2.007 20 .552 12
8 Texas A&M 5-2 .234 6 .182 16 .319 27 .315 9 9.3 3.7 .689 4 -.149 47 1.747 23 .540 20
9 Wisconsin 5-1 .233 4 .445 1 .476 61 .520 48 9.3 4.1 .618 6 -.364 23 -.366 73 .541 18
10 Oregon 5-1 .224 14 .259 7 .294 18 .384 25 8.6 3.8 .527 11 -.623 8 .585 46 .482 79
11 Oklahoma 6-1 .224 3 .280 6 .553 83 .193 2 9.2 3.1 .353 22 -.566 11 -.347 72 .567 5
12 Kansas State 6-0 .218 19 .208 11 .396 43 .258 3 8.0 3.2 .133 45 -.791 1 2.330 18 .583 3
Rk Team FBS
W-L
FEI Last
Wk
GE GE
Rk
SOS
Pvs
Rk SOS
Fut
Rk FBS
MW
FBS
RW
OFEI Rk DFEI Rk STE Rk FPA Rk
13 Arkansas 5-1 .211 12 .105 29 .290 17 .266 5 8.2 3.7 .246 30 -.165 45 .848 41 .478 83
14 Arizona State 4-2 .207 15 .086 36 .331 30 .920 110 9.2 4.9 .534 10 -.445 16 -.585 75 .511 46
15 Miami 3-3 .207 21 .046 46 .312 24 .586 59 8.3 4.2 .867 2 .183 82 3.598 4 .507 50
16 USC 6-1 .203 44 .105 28 .364 35 .399 29 9.2 3.7 .535 9 -.313 30 .663 44 .536 21
17 Michigan 6-1 .177 16 .233 9 .419 49 .542 56 9.3 3.7 .485 15 -.413 20 -3.751 110 .488 71
18 Rutgers 4-2 .166 17 .081 37 .539 82 .798 89 8.6 4.1 -.112 74 -.752 2 3.139 8 .549 13
19 Virginia Tech 6-1 .163 25 .117 23 .432 55 .651 69 8.0 2.9 .229 33 -.397 21 -.237 69 .534 24
20 Southern Mississippi 5-1 .153 24 .117 24 .789 107 .894 99 9.6 4.6 -.060 66 -.536 13 -1.385 89 .490 70
21 Notre Dame 4-3 .150 13 .123 20 .284 16 .446 38 7.7 3.5 .524 12 -.438 18 -.712 78 .480 82
22 Ohio State 4-3 .147 22 .102 33 .256 12 .425 32 7.5 3.1 -.135 81 -.587 9 3.232 7 .578 4
23 Texas Tech 4-2 .142 49 .105 30 .306 23 .480 44 7.1 3.2 .473 16 -.058 53 1.495 27 .492 66
24 Florida State 3-3 .141 33 .105 31 .317 26 .669 72 7.5 3.7 .140 44 -.324 27 2.854 11 .519 39
25 Houston 6-0 .141 29 .220 10 .770 105 .913 105 9.8 4.6 .563 7 .080 71 -.227 68 .517 43

Posted by: Brian Fremeau on 26 Oct 2011

4 comments, Last at 27 Oct 2011, 9:54am by nattybumpo

Comments

1
by mm (not verified) :: Wed, 10/26/2011 - 6:52pm

Oklahoma State ranking 41st in OFEI and 4th in DFEI is a surprising result. Got to hand it to opponent adjustments.

2
by Kal :: Wed, 10/26/2011 - 8:29pm

It's not just opponent adjustments. Because FEI does a drive-based metric, a lot of the things like number of drives get factored into things. The same happened with Oregon last year as well - their defense didn't seem that awesome but when you looked at it as a drive-based and play-based metric it looked much better.

FEI also values turnovers and doesn't particularly care about drives that eat yards but don't get points, so OSU wins there a bit too.

3
by TomTom (not verified) :: Thu, 10/27/2011 - 1:34am

Oregon, Oklahoma, and Oklahoma St. have better defenses that offenses? Also, all three are better than Alabama? I'm an Oregon fan, and I know our defense is always underrated, but I'm not sure I could convince a SEC homer that Alabama's defense isn't as good as the previously stated teams.

4
by nattybumpo :: Thu, 10/27/2011 - 9:54am

Here is a general question about some of FO's defensive metrics. MSU is 5th in DFEI and 6th in Def S&P+ but only 12th in Def F/+. How is that possible?