FEI Final Pre-Bowl Ratings and Connectivity
by Brian Fremeau
This has been a weird college football season. It hasn't been weird like 2007 was weird, with wild results and earth-shattering upsets seemingly every week that turned over the top ten throughout the season. It has been weird for the opposite reason, in fact.
We have four undefeated teams heading into bowl season, including three power programs. No power programs made it to bowl season without a loss last year, and only three total had accomplished that feat in the three years prior. There were five undefeated teams heading into bowl season way back in 2009, but three of those five hailed from non-power conferences. Going undefeated through the regular season is rare. This year, with Alabama, Clemson, Notre Dame, and Central Florida all accomplishing the feat, is especially rare.
The 2018 season has been largely devoid of drama. Alabama, Clemson, Notre Dame, Georgia, Ohio State, Oklahoma, and Washington all finished the pre-bowl season ranked among the top eight teams in the FEI ratings. They're also seven of the top nine teams in the College Football Playoff committee rankings. All seven of those teams were projected as top-eight FEI teams at the beginning of the year. I can't even boast about that prediction -- I didn't really go out on a limb with any of the picks. Six of those teams appeared among the top seven teams in the preseason AP Top 25 poll as well. If it felt like there weren't many surprises this year, you're absolutely right, there weren't.
Back in Week 10, I highlighted another oddity of this season, which is likely related to the lack of drama at the top of the rankings. There seems to be a drop-off in quality after the top tier. Good teams -- the teams that fill out the second half of top-25 polls -- haven't been performing like good teams usually do. Instead, they performed more like the next tier down in quality. That feeds right into the first point – part of the reason why the top teams had staying power this year is that they weren't challenged by the next tier down.
On the subject of the lack of challengers, one of my Twitter followers asked me to look into overall weakness of college football scheduling this year. That kind of inquiry can be approached in a variety of ways. I wanted to see if there was a drop-off in the number of games played between top opponents, suspecting that the lack of drama was also aided by the lack of competition between top teams. My suspicions were confirmed.
I compared the 2018 season with each of the last four years, the College Football Playoff era. Through this past weekend, a total of 733 games between FBS opponents have been played. Only five of those games pitted one top-10 team (according to end-of-year FEI ratings) against another. There were eight such games played prior to bowl season last year, and an average of 7.5 such top-10 matchups from 2014 to 2017. There have been fewer games between top-20 teams played this season than any other playoff year as well. Same goes for games played between top-30 opponents. What is the story here?
The drop-off in games played between top opponents is chiefly tied to non-conference scheduling. The Notre Dame versus Michigan game played all the way back in Week 1 remains the only non-conference game played this year between FEI top-20 opponents. There were seven such games played prior to bowl season last year. There have been only seven non-conference games played between FEI top-30 opponents to date, half as many as last season.
Non-conference scheduling can be fickle. Many teams do make an effort to schedule at least one strong non-conference opponent, and some games that appeared to be matchups between heavyweights prior to the start of the season (Auburn-Washington, Ohio State-TCU, and Notre Dame versus USC, Stanford, Virginia Tech, and Florida State) all turned out to be underwhelming matchups when looked at in retrospect. Scheduling intentions are one thing, but 2018 made many of the non-conference games fizzle when it came time to play those games.
That's disappointing, but it also underscores the tired refrain that "nobody has played anyone" this year. Conference matchups between eight (yes, eight!) SEC teams ranked in the final CFP committee rankings could all look like good games between good teams on paper with ranking numbers assigned to those teams, but appearances can be deceiving. Connectivity between top opponents, and really between all opponents, is more desirable, and not just for the numbers folks like myself who need those inputs to produce reliable outputs. Those games also make college football more interesting. This year wasn't very interesting, and if non-conference scheduling is partially to blame, here's hoping 2018 was an aberration and not the beginning of a trend.
FEI Final Pre-Bowl Ratings
The Fremeau Efficiency Index (FEI) is a college football rating system based on opponent-adjusted possession efficiency. Adjusted Possession Advantage (APA) ratings represent the per-possession scoring advantage a team would be expected to have on a neutral field against an average opponent, calculated as a function of current FEI overall, offense, defense, and special teams ratings.
Strength of Schedule ratings (PSOS) represent the average number of losses an elite team (two standard deviations better than average) would have against the team's schedule to date. Offensive FEI (OFEI) is scoring value generated per drive adjusted for starting field position and opponent defenses faced. Defensive FEI (DFEI) is scoring value generated per opponent drive adjusted for starting field position and opponent offenses faced. Special Teams FEI (SFEI) is scoring value generated per possession by a team's non-offensive and non-defensive units adjusted for opponent special teams units faced. The team's record to date against opponents ranked in the FEI top 10 (v10), top 20 (v20), top 30 (v30), top 40 (v40), and top 50 (v50) are also provided.
Ratings and supporting data are calculated from the results of non-garbage possessions in FBS vs. FBS games.