Dream Season Keeps Rolling for Walker, Spartans
NCAA Week 9 - Kenneth Walker III sprinted, danced, and muscled his way to 197 rushing yards and five touchdowns as Michigan State rallied to beat Michigan 37-33 on Saturday, surging the 8-0 Spartans into College Football Playoff contention and Walker to the top of the Heisman Trophy race. The Wolverines took what looked to be a firm 30-14 lead midway through the third quarter over Michigan State, owning a yards per play advantage of 1.4 and an available yards percentage advantage of 33% to that point in the game. Michigan could not close it out from there, however, netting a punt, a field goal, a fumble, a turnover on downs, and an interception on their final five possessions. Walker scored touchdowns runs of 1 yard, 58 yards, and 23 yards over the same stretch to gut out the comeback win.
Michigan State's dream season to date earned a coveted top-four ranking at No. 3 in the CFP initial rankings release Tuesday, and the Associated Press poll has Sparty ranked at No. 5. FEI and F+ rankings, however, have Michigan State ranked well outside the top 10 this week. What are our opponent-adjusted efficiency numbers seeing differently than everyone else?
It starts with preseason projections, which still account for 18% of this week's FEI ratings for teams like Michigan State that have only played seven FBS opponents. The Spartans have already won 2.1 more FBS games than our modest preseason projections expected, and we were actually higher on their chances than the preseason betting lines by almost a game and a half. They have surprised everyone this season and have significantly exceeded expectations, and our forward-facing numbers are still somewhat skeptical that they can keep it up through the duration of the season.
Their unadjusted efficiency numbers have also been OK but not spectacular through the first two months of the year. Michigan State has certainly shown bursts of big-play potential on offense, but their points per drive, available yards percentage, touchdown rate, and first down rate all rank outside of the top 40 in the country. They have been a boom-or-bust team offensively all year, ranking among the top 10 nationally in plays of 50 or more yards but ranking 99th in busted drive rate, the percentage of drives that result in a drive gain of zero or negative yards. The Spartans defense has not been special either, allowing 75% of opponent drives to earn at least one first down (90th in the nation) and allowing 46% of available yards (60th).
The most important thing in East Lansing, of course, is that they are winning. Possession efficiency and opponent-adjusted performance measures do not matter in their pursuit of a Big Ten championship; only the game outcomes, win or lose, will matter. That is also how teams earn playoff berths. The selection committee process has been a mystery to many over the years, but they have very consistently rewarded teams with a strong collection of pelts on the wall, regardless of how dominant or non-dominant those wins might have been along the way.
Beginning this week, I published a new page of data on my site under the header Record Splits, breaking out win and loss data into categories that more closely match what the selection committee prioritizes. The answer to the question of which teams are best is substantially different from the answer to the question of which teams have the best collection of wins. Michigan State is a great example of this distinction. The Spartans rank 20th overall in FEI (a measure of "best") but rank right behind Georgia in every Win Rating and Degree of Difficulty Rating ("most deserving") produced from the same FEI data. Record Splits suggest the Spartans have absolutely earned their playoff positioning to date. FEI suggests that Georgia would be heavily favored against them anyway.
The road ahead for Michigan State is treacherous, and unless their efficiency numbers peak in November, it will take even more good fortune for them to remain undefeated and claim a Big Ten East title. The Spartans have only a 5% chance of running the table through the regular season, with a road trip to Purdue this week (51% win likelihood), followed by a home game against Maryland (85%), a trip to Ohio State (21%), and wrapping up at home against Penn State (53%). Perhaps the dream season will keep rolling, but my numbers are not counting on it. But even a 2-2 finish, disappointing as that would be given the potential for more, would be a very special season for Michigan State.
2021 FEI Ratings (through Week 9)
FEI ratings (FEI) represent the per-possession scoring advantage each team would be expected to have on a neutral field against an average opponent. Offense ratings (OFEI) and defense ratings (DFEI) represent the per-possession scoring advantages for each team unit against an average opponent.
Preseason projected ratings are progressively phased out over the course of the season. Expanded ratings for all teams include overall, offense, defense, and special teams efficiency ratings. Ratings and supporting data are calculated from the results of non-garbage possessions in FBS vs. FBS games.