The Florida State Seminoles are the most productive team after the first three weeks of the college football season, according to a weekly ranking that measures offensive and defensive production compiled by a University of Iowa economist.
Stacey Brook, who teaches economics in the Tippie College of Business, compiles his top 25 teams by using an exhaustive formula that measures their offensive and defensive productivity. After all, he says, economists, stock analysts, and management experts measure a firm’s performance based on its production, so why not apply the same measures to college football teams.
Following FSU in his ranking is Texas Tech and Oklahoma State. Alabama and LSU, ranked 1-2 in the AP and USA Today polls, are 4 and 5 in the Brook ranking.
The Big Ten, meanwhile, has only one team, and just barely. Ohio State is ranked 25.
For his own ranking, Brook started with the presumption that productive teams—and, hence, better teams—score more points than their opponents and give up fewer points.
“Then I stepped back and asked, how do teams score points, and how do they keep their opponents from scoring points?” he says. After examining several measures, he finally settled on 17 statistics that best measure a team’s productivity on each side of the ball, including yards gained, number of first downs, touchdown scoring percent, number of offensive plays, missed and made field goals, and turnovers. This season, it also takes into account the teams’ conferences.
He then plugs those numbers into two lengthy formulas, one to measure offensive productivity and one to measure defensive productivity. Some statistics are weighted because his research has found that they are more important to a team’s success.
Subtracting defensive production from offensive, he arrives at a list of the most productive teams.
And that’s when eyebrows can start going up because his survey produces some curious divergences from the polls (he lists each week’s latest rankings on his blog at teamsportsanalysis.blogspot.com/). For instance, Brook’s ranking has Iowa State at 18, even though it’s nowhere to be found in the polls. Meanwhile, USC is ranked 13th by AP but is absent from Brook’s list entirely after a loss at Stanford and a poor game against Syracuse lowered its overall productivity.
“There are some counter-intuitive results, to be sure,” he says.
But he says such divergences are the inevitable result of using polls to measure something without first adequately defining what should be measured. Brooks’ own formula takes into account 17 statistical measures and is weighted toward possession, turnovers, and total yardage. But the people who vote in the polls—coaches in some, sportswriters in others—each have their own formulas that consider different factors. Some may favor total points or overall yardage, some may vote based on how the coach treats the voter during the post-game press conference or how cute the school mascot is. Whatever it is, it’s likely different from Brook’s, and different from the other poll voters.
“Voter bias and the degree to which they’re biased definitely has an impact on how the rankings turn out,” says Brook.
Iowa, by the way, is ranked 55, two spots better than Michigan State, which had been picked by some pre-season prognosticators to be a national title contender.