FEI Week 7: Game Factors
by Brian Fremeau
The top three teams in the FEI ratings last week all lost over the weekend. Arizona (No. 1 last week) missed a two-point conversion attempt late in the fourth quarter and a field-goal attempt as time expired to fall to USC for their first loss of the year. UCLA (No. 2 last week) lost to Oregon 42-30 in a game where the Bruins trailed by 32 points with 10 minutes left in the fourth quarter. And TCU (No. 3 last week) lost to Baylor 61-58, giving up 24 straight points to the Bears over the final 11 minutes of the game.
The weekly ratings were rocked once again as a result. The average team in the FEI top 25 changed seven spots each from last week to this week, due not only to upsets but also to the elimination of preseason projection data from the FEI formula. From this point forward, only 2014 game data is included in the FEI calculations. Instability may still reign, of course. Through the first seven weeks of the season, there have been 36 upsets against teams that were favored by at least a touchdown heading into the game, a 50 percent increase in such upsets over the same span last season.
Beginning this week, I've also published opponent-adjusted offensive efficiency (OFEI) and opponent-adjusted defensive efficiency (DFEI) data. The defensive leaderboard doesn't feature many major surprises. Louisville leads all teams in DFEI, and also leads most unadjusted measures including first down rate (allowing a first down on only 38.8 percent of opponent drives), available yards surrendered (21.2 percent), explosive drive rate (1.2 percent), and value drive rate (15.7 percent). The Cardinals rank second nationally in points allowed per drive (0.67) and No. 1 in points allowed per value drive (2.55).
The offensive leaderboard is a bit more startling. The UCLA Bruins rank No. 1 in OFEI through the first seven weeks of the season, despite ranking only 28th in yards per game and 34th in scoring per game, 48th in available yards, and 63rd in value drive percentage. What does the FEI formula like about those numbers? As with many FEI questions, it all comes down to the opponent adjustments.
UCLA has faced the No. 3, No. 9, No. 21, No. 31, No. 34, and No. 54 defenses so far, a group of opponents that represents the No. 2 offensive strength of schedule to date. Four of UCLA's raw offensive efficiency performances to date rank among the top 200 offensive games played in college football (out of 678 total performances). When adjusted for opponent, all six of their offensive performances to date rank among the top 200, and four rank among the top 30. Washington State is the only other team with four games ranked in the top 30 of OFEI. Only three other teams (Arizona, Miami, and North Carolina) have at least two such games.
Every offensive, defensive, and overall single game performance is ranked in the FEI Game Factors data I publish on my site. In addition to the raw and opponent-adjusted data and game ranks, the relevance of each data point in the FEI formula is also provided. For UCLA, more weight is given to their upset loss to Utah (19.9 percent of the Bruins' FEI rating) than to their win over Texas (11.5 percent). Game weights are unique to each team and are a function of the relative strength of opponents faced. Mississppi's win over Alabama (25.6 percent of the Rebels' rating) is given nearly five times as much weight as its win over Louisiana Lafayette (5.5 percent).
Unlike Game Splits, which represent measures of value generated by offense, defense, special teams, field position, and turnovers, the Game Factors data changes as the season progresses. As UCLA's opponent ratings change, the relative success the Bruins had in their games against those opponents will also change.
Last year, the national champion Florida State Seminoles finished the season with eight of the top 100 opponent-adjusted single game performances of the year. Five teams each have four top-100 GFEI performances to date so far, and all five teams rank among the top 15 in FEI: No. 2 Ole Miss, No. 3 USC, No. 9 Stanford, No. 11 Oklahoma, and No. 13 Auburn. Six others have each recorded three top 100 GFEI performances to date: No. 4 TCU, No. 7 Georgia, No. 8 Baylor, No. 20 Clemson, and No. 34 Washington State. The lowest ranked team with at least two top 100 GFEI performances to date is Texas. Both of those games were close losses to highly ranked opponents (UCLA and Oklahoma). Four other Longhorns games were average or below-average performances.
Game Factors are the opponent-adjusted guts of each team's FEI rating. If you aren't sure why FEI thinks your team is overrated or underrated, the answer can be found in the Game Factors data. Opponent adjustments are very meaningful in this system, and some individual games carry significant weights at this point in the year.
FEI 2014 Week 7 Ratings
The Fremeau Efficiency Index (FEI) is a college football rating system based on opponent-adjusted drive efficiency. Nearly 20,000 possessions are contested annually in FBS vs. FBS games. First-half clock-kills and end-of-game garbage drives and scores are filtered out. Game Efficiency (GE) is a function of the starting field position and outcome of non-garbage possessions. Opponent adjustments are calculated with special emphasis placed on quality performances against good teams, win or lose.
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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 listed here includes all regular season games scheduled. A multifaceted approach to measuring schedule strength is available here and visualized here.
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 total games a team with the given FEI rating should expect to win against the remaining opponents on its schedule.
Offensive FEI (OFEI) is opponent-adjusted offensive efficiency. Defensive FEI (DFEI) is opponent-adjusted defensive efficiency. Special Teams Efficiency (STE) is the composite efficiency of field goal kickoff, punt, and return units. Field Position Advantage (FPA) is the average share of field position value generated by offense, defense, and special teams efficiency.
These ratings are exclusively produced from 2014 game data and are not influenced by preseason projections. Complete ratings and ratings splits for all 128 FBS teams are available here. Supplemental data including points per drive, game splits, and game factors are available as well.