The Bears produce
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Five weeks into the 2013 college football season, the Baylor University Bears are the most productive team 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 Baylor in his ranking come Oregon, Louisville, Florida State, and Washington. Alabama, ranked number 1 in both the AP and USA Today polls, is only at 31 on Brook’s ranking.
“Alabama has not played as well on defense as they have in the past,” he says. “ Since 2009, Alabama’s defense has been ranked in the top five, sometimes number one, and this year they are currently ranked 30 overall.”
He expects Alabama to start rising as conference play begins and other defenses—like Baylor’s—play tougher teams that lower their own defensive productivity. Alabama’s defensive will then rise relatively to other teams reduced productivity.
Iowa is ranked at number 20. Michigan State, the Hawkeye’s opponent in this weekend’s Homecoming game, is ranked 18.
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. After examining several measures, he finally settled on 18 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. For instance, Houston checks in at 13 in Brook’s ranking, but is nowhere to be found in the polls, while Northwestern is at 16 in the AP poll and in 15 in the USA Today, but misses Brook’s top 25.
He said such divergences are the inevitable result of using polls to measure something without first adequately defining what should be measured. Brooks’ formula uses statistical measures and weighting, but the people who vote in the polls each have their own formulas.