by Brian Fremeau

Before the season began, I discussed the 90th percentile as a way to evaluate the teams that produce elite opponent-adjusted single-game results at a high rate. The postseason championship contenders first need to navigate their regular seasons with as few losses as possible to even merit consideration for the playoff, but which teams showcase their potential to play at an elite level most often?

Bill Connelly uses percentile performances based on S&P+ ratings in his Varsity Numbers columns, and I have my own that are based on my FEI ratings. There are similarities between our two approaches, and similar results. Clemson is the top-ranked team in each of our respective rating systems by a wide margin. Bill credits the Tigers with 90th percentile performances against FBS opponents Appalachian State, Georgia Tech, and Miami. My numbers agree with those games and add in the victory over Notre Dame as a 90th percentile performance as well.

Clemson's dominating win over Miami in Week 8 actually ranks as the No. 2 opponent-adjusted game efficiency result of the season. The best GFEI rating of the season to date is Utah's 62-20 victory over Oregon back in Week 4. In neither case does the opponent rank very highly in FEI -- Oregon has slumped down to No. 47 and Miami sits at No. 53. Both wins were extremely efficient, of course, and that combination of efficiency and opponent strength is the key to the GFEI results and therefore the overall FEI ratings.

Efficiency against a strong opponent, even in a losing effort, is rewarded in the FEI formula. Notre Dame has the third best GFEI rating of the season in its 22-24 loss on the road against Clemson in Week 5. Few Irish fans would likely view the loss to the Tigers as Notre Dame's best performance of the year, but my formula is designed to give more credit to a narrow road loss to an elite opponent than to a dominant win over an overmatched opponent. Notre Dame's 38-3 win over Texas (FEI No. 73) was very good, but it only ranks in the 85th percentile in my GFEI ratings.

Clemson and Notre Dame are two of the seven teams this season that have recorded four 90th percentile GFEI results to date. As one would expect, the teams at the top of this list are also at the top of the FEI ratings. All teams with at least two 90th percentile performances to date are included.

Tennessee has a losing FBS record but still ranks among several of the playoff challengers in terms of 90th percentile performances to date. Two of their 90th percentile performances came in road losses -- a one-point defeat at Florida and a five-point defeat at Alabama. USC has three losses on the season, but four 90th percentile performances (including three straight since Steve Sarkisian was fired). Undefeated Baylor, Iowa, and Memphis have one 90th percentile GFEI result apiece. Oklahoma State and Houston have none so far.

Every team has an opportunity to post a 90th percentile GFEI result in any given week, regardless of the strength of the opponent, but the GFEI ratings make clear that it is much tougher to do so against weak opposition than against strong opposition. As the final month of the season plays out, some playoff contenders will have their first opportunities to deliver 90th percentile results -- to impress selection committee members and to underscore their capacity to play like one of the elite teams in the nation.

FEI Degree of Difficulty through Week 9

FEI Degree of Difficulty (DOD) ratings are based on current FEI ratings, but instead of measuring efficiency against schedule, DOD measures record against schedule. What is the likelihood that an elite team (two standard deviations better than average) would play a given team's schedule to date and achieve that team's record?

My hypothesis is that the College Football Playoff selection committee is likely to value and reward something akin to DOD through their process and deliberations. As of this week, the following teams have the best records relative to the schedule each has faced to date. Each team's current FEI rating, remaining strength of schedule (RSOS) rating, and current College Football Playoff ranking (CFP) are also provided. DOD ratings for all teams can be found here.

FEI Week 9 Ratings

The Fremeau Efficiency Index (FEI) is a college football rating system based on opponent-adjusted drive efficiency. Approximately 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. Unadjusted game efficiency (GE) is a measure of net success on non-garbage possessions, and opponent adjustments are calculated with special emphasis placed on quality performances against good teams, win or lose. Other definitions:

• SOS: Strength of Schedule, measured as the likelihood of an elite team going undefeated against the given team's regular season schedule. Schedule strength data based on FEI ratings and calculated across other dimensions can be explored in this interactive visualization.
• FBS MW: Mean Wins, the average number of games a team with the given FEI rating would be expected to win against its regular season schedule of FBS opponents.
• FBS RMW: Remaining Mean Wins, the average number of games a team with the given FEI rating would be expected to win against the remainder of its regular season schedule of FBS opponents.
• OFEI: Opponent-adjusted Offensive Efficiency value generated per possession.
• DFEI: Opponent-adjusted Defensive Efficiency value generated per opponent possession.
• STE: Special Teams Efficiency value generated per game possession.
• FVE: Field Value Efficiency value generated per game possession.

Preseason projection data receives no weight in this week's ratings. Ratings for all FBS teams can be found here.

Posted by: Brian Fremeau on 04 Nov 2015

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