FEI Week 3: Turnover Margins

by Brian Fremeau

The third weekend of the season featured several major statement victories from potential national championship contenders, including a handful of key road victories from teams at the top of the FEI ratings.

Alabama fell behind Ole Miss by 21 points in the first half in Oxford before rallying to a 48-43 victory, the largest comeback victory by the Crimson Tide under head coach Nick Saban and the program's first comeback win by 17 or more points since at least 2007. Michigan State dominated Notre Dame in South Bend for three quarters, mounting a 29-point lead before fending off a late rally to win 36-28. Ohio State rolled over Oklahoma in Norman. Houston danced with disaster at Cincinnati before dominating the fourth quarter to win by 24 points.

The road wins by the Spartans, Buckeyes, and Cougars -- along with another dial back in the weight given to preseason projections (now at 57 percent) -- pushed those teams into three of the top seven spots in this week's ratings, while Alabama remained on top by a healthy margin.

Four of the Power 5 conferences are represented in the FEI top 15. We have five teams from the SEC, four from the Big Ten, three from the ACC, and two from the Pac-12. The power conference absent from that tier is the Big 12, a league that has combined to win only two games to date against FEI top-50 opponents (Texas over Notre Dame in Week 1, and Oklahoma State over Pittsburgh in Week 3).

Texas fell on the road late Saturday night against California, a game in which they jumped out to 24-14 lead early in the second quarter, but then gave up touchdowns on four of the next five Bears possessions to fall behind before halftime. Two of those touchdowns came on California's best starting field position situations of the night -- a five-play, 46-yard score and a two-play, 24-yard score after a pair of Texas interceptions. There were no other turnovers in the game.

Turnover counts are a broad-brush statistic, but they're a popular and useful reference point for coaches and fans alike to explain the results of a given game. In FBS vs. FBS games since 2007, the team that recorded a positive turnover margin went on to win 74.5 percent of the time. That win rate jumps up to 82.5 percent when the turnover margin was plus-2 or better. (Turnovers are collectively defined here as fumbles that result in a change of possession, interceptions, and successful onside kick attempts).

For Texas, a two-turnover deficit has proven to be particularly costly. The Longhorns have had a turnover margin of minus-2 or worse in 26 FBS games since 2007, and they have won only two of those games (.077 win percentage). In all other games in that span, the Longhorns are 76-17 (.817). Among FBS teams in the last ten years, that's the biggest win percentage delta between minus-2 or worse turnover games and all other games.

Another team worth mentioning in terms of poor turnover margins is Notre Dame. In their loss this weekend to Michigan State, the Irish coughed up the ball three times (a punt return miscue, a fumble, and an interception) and only forced one Spartans turnover. It was the 32nd occasion since 2007 that Notre Dame was minus-2 or worse in turnover margin. The Irish have managed to win a decent percentage of those games (.313) compared to the national average (.175), but they have had to dig themselves out of a deep turnover hole far too often. Among the top 60 teams in FBS win percentage since 2007, Notre Dame ranks behind only Nebraska (33 games) in the number of occasions in which it has been minus-2 or worse in turnover margin.

• Click here for game results by turnover margin data for all teams since 2007.

FEI Ratings Through Week 3

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. Overall SOS ratings represent the likelihood than an elite team (two standard deviations better than average) would go undefeated against the given team's entire schedule.

FEI ratings through the first six weeks of the season are based in part on preseason projection data. Preseason ratings represent approximately 57 percent of this week's ratings. Ratings for all teams are linked here.