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.

Posted by: Brian Fremeau on 26 Oct 2011

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