FEI Week 15 Ratings
The 2019 College Football Playoff field is set, following a weekend that held some promise for chaos and playoff drama but ultimately relieved the selection committee of the responsibility of making challenging and difficult decisions. Three teams stand head and shoulders ahead of the nation, and the fourth team is the best of the rest.
LSU dominated Georgia in the SEC Championship Game, an especially impressive showcase of LSU's offensive prowess against one of the nation's most efficient defenses coming into the contest. Ohio State faced its first major challenge of the year, falling behind Wisconsin by 14 points at halftime of the Big Ten Championship Game, but the Buckeyes rallied and overwhelmed the Badgers in the second half to ultimately claim the title in comfortable fashion. Clemson once again faced an overmatched opponent and once again completely destroyed that opponent, crushing Virginia by 45 points in the ACC Championship Game. Oklahoma solidly outplayed Baylor for most of the Big 12 Championship Game, but a few big plays by the Bears helped push the game into overtime when the Sooners finally prevailed. And in the Pac-12 Championship Game, Utah forfeited its opportunity to wedge itself into the playoff picture by falling to Oregon.
The committee didn't need to make any particularly tough choices, but I think it's still beneficial to examine their work. Every year, the College Football Playoff selection committee is comprised of a different cohort of individuals, and though there are weekly talking points shared with the public, we do not have a crystal-clear picture of their deliberations. Some very interesting work has been done by Dave Bartoo (a.k.a. CFBMatrix) to zero in on the "formula" used by the committee, and he has a strong track record of accurate playoff ranking predictions. The committee rankings closely resemble his forecasts each week, but I'm not as convinced as he is that the committee is following an actual formula. Instead, I think he has simply zeroed in on what the committee values most, and it isn't very complicated.
The playoff selection committee may be officially charged with selecting the four best teams for the national semifinals, but in practice they select the four most deserving teams. They prioritize zero-loss and one-loss records by Power 5 teams more than they prioritize dominance or efficiency. And they prioritize "pelts on the wall" more than they prioritize the manner in which those wins were achieved. These are not criticisms of the committee's priorities -- in practice, these priorities are generally consistent with college football fans at large.
I've recently published "College Football Playoff Team Profile" data on my site as an attempt to quantify elements of the selection committee's priorities. These aren't intended to be predictive of the CFP rankings themselves. Instead, it is a means to share and consider the data that would support or not support a team's "most deserving" playoff candidacy, and to consider that team's profile against not only the other national championship contenders, but against every other FBS team by the same measures.
The first bucket in my playoff team profiles is under the header of "game types." How often has each team played like an elite team? How often has it played like a merely good or above-average team? How often, if at all, has it played like a below-average team? I'm quantifying the answers to these questions by comparing each team's non-garbage results to the expected results of an elite (two standard deviations better than average), good (one standard deviation better than average), or average team against the same opponents. In this bucket, unsurprisingly, LSU, Ohio State, and Clemson stand apart from everyone else in 2019 -- and they stand apart from most of the playoff fields of each of the five previous seasons as well. The Buckeyes have had a whopping 12 "elite" performances this season, and only one merely "good" performance. (And that one merely good performance came in a blowout victory over Rutgers. The Buckeyes led 42-7 through 23 non-garbage possessions, whereas an elite team would have been expected to tally a 50-point lead over the same span. For shame.) LSU and Oklahoma each have nine elite performances to date. None of the members of either the 2014 or 2015 playoff fields racked up as many elite performances as LSU, Ohio State, or Clemson did this year, and only last year's playoff field featured even two teams with comparably impressive season's heading into the postseason. This is also the only playoff field to date in which none of the four teams had a single "below-average" game performance coming into the playoff -- Oklahoma racked up only five elite performances to date, and did suffer an upset loss to Kansas State, but even that loss measures as better than an average team would have been expected to do against the Wildcats.
The second bucket in my playoff team profiles is under the header of "strength of record," and there are three different perspective ratings shared in this category. How does each team's collection of wins (not performance, just victory or defeat is considered) compare to what an elite, good, or average team would have expected to achieve? Of all of the data in the team profiles, these categories have trended most closely with selection committee priorities since 2014. Of the top four teams in EAW (elite-adjusted wins) in each of the six playoff years, only three did not reach the playoff. Of the top four teams in GAW (good-adjusted wins), only two did not reach the playoff. Only two of the top four in AAW (average-adjusted wins) did not reach the playoff in the last six years as well.
The third and final bucket in my playoff team profiles is under the header of "strength of scores," and I'm sharing this breakdown for the first time in this format. The idea is that each team's average game score (AGS) represents on average how well it did or did not play relative to how an average team would have been expected to play. Ohio State's 48.0 AGS means that on average, when adjusted for the strength of its opponents and adjusting for an average number of possessions per game, the Buckeyes were 48.0 points better than an average team per game. Clemson was 41.5 points better per game than an average team. LSU was 39.3 points better than an average team. Those numbers underscore how strong this field is, not only relative to the rest of the country in 2019 but also to the playoff fields since 2014. According to AGS, the four best teams heading into the postseason over the last six years would include three teams from 2019. Only the 2018 Alabama Crimson Tide (49.6 AGS) rank among them.
That last point is one worth remembering as we ramp up to the national semifinal games. This year's playoff field is as impressive on paper as ever, but these teams are not invincible. As Clemson proved in their dominating victory over Alabama last year in the championship, even teams with the best pre-playoff statistical profiles can be taken down in convincing fashion in a head-to-head matchup on the biggest stage. This year's playoff includes teams that have been as impressive in the regular season as any in recent memory. Here's hoping each brings its best to the table later this month.
2019 FEI Ratings (through Week 15)
The Fremeau Efficiency Index (FEI) is a college football rating system based on opponent-adjusted possession efficiency, representing the per possession scoring advantage a team would be expected to have on a neutral field against an average opponent. Unadjusted possession efficiency (PE) is calculated as a function of offensive, defensive, and special teams game splits. Schedule strength is represented by each team's average per possession opponent adjustment (OA). Opponent-adjusted offense ratings (OFEI), opponent-adjusted defense ratings (DFEI), and opponent-adjusted special teams ratings (SFEI) are calculated in a similar manner as overall FEI ratings. Team records against all FBS opponents (W-L) and 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.