As the title implies, we are about to go down a road that will inspire debate and we expect considerable hate. As we suspected, and have since confirmed in our 3 months of publishing, there is no sport with more passionate fans than college football. We know that as soon as we provide our ranking of college coaches that we will immediately be told that we are wrong (and in rare cases that we are right).
For our coaching analysis, the starting point is the idea that we should rank coaches’ performance relative to the resources that are at their disposal. In other words, we can’t compare the coaches at the University of Illinois and the University of Florida simply based on win-loss records. For the analysis, we gathered data on results (winning percentage, major bowl participation), football expenditures, historical performance (won-lost records, major bowls, national championships, etc…), attendance and other factors.
We use this data to create models that predict team success based on financial resources, historical performance and market potential. These factors can all contribute to on-field success. For example, the logic of including historical performance is that a more storied program may be more attractive to both bowls and to potential recruits. We use the models to predict the performance of each school for each of the last 10 years. We then assess the contribution of the coach by comparing actual to predicted performance.
We analyzed coaches using the past 10 years of data in terms of two criteria: winning percentage and selection to play in a major bowl (Rose, Orange, Fiesta, Sugar, and National Championship). As an aside, our performance models were both estimated using logistic regression.
In terms of incremental winning percentage effects, the top coach was Chris Petersen from Boise State. Coach Petersen has achieved a 91.3% winning percentage while at a school with only moderate football expenditures (even among non-BCS schools) and limited history. In terms of specific numbers, we find that Petersen has achieved a winning percentage that is 37% higher than what a school of comparable resources and history achieves. The top five also includes Urban Meyer, Brian Kelly, Bret Bielema and Bobby Petrino. In positions six through ten we have Steve Spurrier, Bob Stoops, Gary Patterson and Frank Beamer. Two other former coaches produced notable results on the winning percentage criterion. Chip Kelly won 32% and Pete Carroll won 13.3% more games than expected.
Okay so who is missing?
We already anticipate complaints from Alabama fans along the lines of “The list is invalid because at Alabama we play for championships, not for winning an incremental game or two.” Well, Coach Saban does finish 11th on the incremental winning list, and there is some merit to this argument. It is more difficult to drive incremental wins at schools like Alabama than Boise State.
In part two of our analysis we looked at incremental participation rates in BCS bowl games (not just the BCS championship). Our approach was similar as in the winning percentage analysis and used the same set of predictor variables. On this metric, the top performer was Bret Bielema. Bielema’s record includes taking Wisconsin to the last three Rose Bowls. In terms of percentages, we find that with Bielema in charge, Wisconsin improved their rate of BCS bowl participation by 28%. It looks like Arkansas made a great choice! In positions two through five we have Chris Petersen, Bob Stoops, Frank Beamer and Urban Meyer. And where does Coach Saban fall? Just behind Urban Meyer in 6th place.
If we also look at former college coaches one name really stands out. Chip Kelly was by far the leader on the BCS bowl participation metric. Combined with the winning rate results, one can argue that Chip Kelly has been the most effective college coach over the past few years.
Returning to Coach Saban, first, it must be noted that he scores really well on our measures (11th for incremental wins and 6th for incremental BCS games). And we definitely understand the argument that he should be number one. In terms of winning championships, it is hard to argue that he is not the go-to coach.
Mike Lewis & Manish Tripathi, Emory University, 2013.