TCU has played much better in the second half of games this year. What other schools have seen dramatic shifts of play after halftime?
13 Nov 2013
by Brian Fremeau
Last weekend had been earmarked as one of the most important of the college football calendar as soon as team schedules were released in the off-season. The battle for SEC West supremacy between Alabama and LSU has had major BCS championship implications in each of the last five seasons. Oregon and Stanford have been perennial top-10 programs since 2010, and their Pac 12 North rivalry has factored heavily into the national championship race as well.
Both games featured top-10 teams according to last week’s FEI ratings. And the victories by Alabama and Stanford in those games were important factors in the Crimson Tide and Cardinal vaulting over Florida State in this week’s FEI ratings. But they certainly weren’t the only results that mattered.
We can figure out which games mattered most by taking another close look at Game Factors, the single-game opponent adjusted efficiency data that produces each team’s overall rating. Opponent-adjusted overall game efficiency (GFEI), offensive efficiency (OFEI), and defensive efficiency (DFEI) are provided for every team in every game, and the weight each game receives in the formula is provided as well.
Let’s begin with Alabama. The Crimson Tide now have four wins over FEI top-25 opponents (No. 14 Virginia Tech, No. 15 Texas A&M, No. 22 LSU, No. 25 Mississippi). All four games rank in the 97th percentile of all overall team performances played to date this season. Based on the weight given to those games in the FEI formula, those four results account for 64.5 percent of Alabama’s FEI rating.
|FEI Game Factors - Alabama Crimson Tide|
|Alabama||1||Virginia Tech||W 35-10||W 35-10||.660||5||1.600||61||-.542||146||.170|
|Alabama||3||Texas A&M||W 49-42||W 49-42||.542||26||2.020||17||.121||406||.166|
|Alabama||4||Colorado State||W 31-6||W 24-6||.137||346||-.004||693||-.405||186||.093|
|Alabama||5||Mississippi||W 25-0||W 25-0||.576||14||1.035||193||-1.436||4||.151|
|Alabama||6||Georgia State||W 45-3||W 38-3||.287||181||.638||355||.063||378||.042|
|Alabama||7||Kentucky||W 48-7||W 34-7||.321||156||.090||650||-.470||167||.072|
|Alabama||8||Arkansas||W 52-0||W 35-0||.460||56||1.055||185||-.550||143||.068|
|Alabama||9||Tennessee||W 45-10||W 42-3||.525||34||1.255||129||-.413||184||.080|
|Alabama||11||LSU||W 38-17||W 38-17||.644||7||1.790||32||-1.271||7||.158|
A blowout win over Tennessee is also highly ranked according to GFEI (96th percentile), and that cluster of five victories accounts for 72.5 percent of Alabama’s FEI rating. This cluster of victories is what distinguishes Alabama from the rest of the team resumes compiled by other contenders. The chart below plots the GFEI distribution for the Crimson Tide over each of the last five weeks. You can see how the cluster of Alabama’s best games to date has been built over time.
This chart helps illustrate the changes in opponent adjustments for each game in each week as well. While the cluster of top victories has been relatively consistent over the last month, some of the individual GFEI results have had a big impact. Which win has been Alabama’s best according to GFEI? The opening weekend victory over Virginia Tech is the answer to that question this week, but that particular result has varied considerably over the last month.
The Hokies were ranked No. 21 in the Week 7 FEI ratings, 5-1 against FBS opponents at the time. A win over Pittsburgh bumped them up in Week 8 and a close loss to Duke in Week 9 didn’t significantly change their profile. But a loss to Boston College in Week 10 dropped Virginia Tech back to No. 24, and as illustrated above, that substantially changed the FEI perspective on Alabama’s win over the Hokies. One week later, the Hokies trounced Miami on the road and the GFEI factor in that game leapt forward once again.
That Virginia Tech win over Miami had a significant impact on the Seminoles as well. A week ago, we discussed how Florida State had recorded three of the top-10 opponent-adjusted single game performances of the season to date. The win over Miami was rated then as the 7th best of the college football season. Once Miami lost to Virginia Tech, however, that win dropped to only the 29th best of the season, and Florida State’s overall profile suffered a bit.
|FEI Game Factors - Florida State Seminoles|
|Florida State||1||Pittsburgh||W 41-13||W 41-13||0.721||3||2.033||15||0.055||369||0.152|
|Florida State||3||Nevada||W 62-7||W 45-7||0.244||233||0.430||474||-0.647||111||0.082|
|Florida State||5||Boston College||W 48-34||W 48-34||0.210||256||0.878||252||0.195||449||0.125|
|Florida State||6||Maryland||W 63-0||W 42-0||0.337||139||2.021||16||0.015||350||0.086|
|Florida State||8||Clemson||W 51-14||W 41-7||0.815||1||1.716||42||-1.022||26||0.176|
|Florida State||9||North Carolina State||W 49-17||W 42-10||0.117||368||1.094||171||0.174||431||0.099|
|Florida State||10||Miami||W 41-14||W 35-14||0.539||29||1.835||25||-1.116||15||0.182|
|Florida State||11||Wake Forest||W 59-3||W 52-0||0.508||40||0.575||385||-0.878||49||0.098|
The Seminoles have a wider distribution of game results than Alabama, and they still have two of the top-3 single-game overall performances (against Clemson and Pittsburgh). As mentioned last week, the end-of-year FEI perspective on the Seminoles may come down to how strong Clemson, Miami, and Pittsburgh finish the year. The Hurricanes didn’t help that cause last weekend.
The new No. 2 team in the FEI ratings is Stanford, fresh off their win over Oregon. That win was impressive (and would have been much more impressive in the eyes of FEI had the Cardinal not allowed a flurry of points from the Ducks late in the game). But shouldn’t Stanford be held back by their loss to Utah? The Utes, of course, are still looked upon favorably in the FEI ratings (hold that thought), though that particular result has been declining in the eyes of FEI over the last month.
|FEI Game Factors - Stanford Cardinal|
|Stanford||2||San Jose State||W 34-13||W 34-13||0.158||322||0.244||584||-0.273||231||0.060|
|Stanford||3||Army||W 34-20||W 34-20||0.018||485||-0.224||801||-0.569||137||0.052|
|Stanford||4||Arizona State||W 42-28||W 39-14||0.794||2||1.746||38||-1.612||2||0.151|
|Stanford||5||Washington State||W 55-17||W 41-3||0.475||54||0.543||406||-0.486||161||0.068|
|Stanford||6||Washington||W 31-28||W 31-28||0.268||203||0.683||342||-0.305||222||0.118|
|Stanford||7||Utah||L 21-27||L 21-27||0.417||78||0.845||270||-0.272||232||0.167|
|Stanford||8||UCLA||W 24-10||W 24-10||0.445||64||1.222||136||-0.905||46||0.123|
|Stanford||9||Oregon State||W 20-12||W 20-12||0.419||74||0.283||558||-0.970||32||0.110|
|Stanford||11||Oregon||W 26-20||W 26-20||0.540||27||1.736||39||-0.982||30||0.150|
In the same span, Stanford’s best win has looked better and better. Arizona State has climbed all the way to No. 4 overall in the FEI ratings this week, and Stanford’s dominant win over the Sun Devils back on September 21st has been elevated to the No. 2 overall single-game efficiency mark of the year.
I feel compelled to discuss Utah one more time (though I certainly cannot promise this will be the last). Utah lost to Arizona State 20-19 over the weekend. All eight of the Utes’ opponents to date are ranked in the FEI top 40, more than any other team. The Utes are one of only eight teams with at least three wins against FEI top-40 opponents. They are one of only six teams with at least two wins over FEI top-20 opponents.
|Victories Over FEI Top-40 and Top-20 Opponents|
I mentioned on Twitter over the weekend that I have been waiting for a team to finally put Utah in its place in the FEI ratings by blowing them out, and I thought the Sun Devils were a good candidate to do so. Instead, Utah grabbed a lead and nearly hung on before Arizona State prevailed in the end. Once again, turnovers doomed the Utes. In four of their five losses, the value lost on turnovers by Utah exceeded their scoring deficit in the game. They would be 7-1 (and ranked seventh) in turnover-neutral FEI.
Oregon is next for Utah. We’ll see if they can play yet another close game against yet another strong opponent. It certainly has the potential to be one of the most influential games in determining next week’s FEI ratings.
The Fremeau Efficiency Index (FEI) rewards playing well against good teams, win or lose, and punishes losing to poor teams more harshly than it rewards defeating poor teams. FEI is drive-based and it is specifically engineered to measure the college game. FEI is the opponent-adjusted value of Game Efficiency (GE), a measurement of the success rate of a team scoring and preventing opponent scoring throughout the non-garbage-time possessions of a game. FEI represents a team's efficiency value over average.
These FEI ratings are a function of results of games played through November 9th. The ratings for all FBS teams can be found here. Program FEI (five-year weighted) ratings and other supplemental drive-based data can be found here.
4 comments, Last at 15 Nov 2013, 5:56am by Brian Fremeau