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Analytics: The Positive Impact Factor

Special to College Football News
Posted Aug 28, 2013


College football is still the “Wild, Wild West” in terms of statistics and analytics. There are so many cutting-edge ways of improving statistical analysis and player assessment. People who study this sport need to use better and more advanced analytical tools in the 2013 season and beyond. One such tool is the Positive Impact Factor.


Dr. Patrick Johnston is a football writer and analyst who has worked for multiple web outlets that cover both college and professional football, including NFL Network. You can follow Dr. Johnston on Twitter: twitter.com/TheRealPSJ

The Positive Impact Factor: A Different Way to Evaluate Quarterbacks

If all a quarterback did was throw the football without being able to fumble or take a sack or even run with the ball, the passer rating would be a fine tool to evaluate his play (albeit one that scales so differently between the college and pro game to make it useless for comparison). However, quarterbacks have more responsibilities than simply passing and can impact games in large ways without passing. (Air Force defeating Hawaii in 2012 without throwing a single pass offers a perfect example.) In order to evaluate quarterbacks who play in vastly different offensive schemes across a league such as the NCAA, I developed the Positive Impact Factor (PIF) in 2009.

Instead of focusing on passing attempts, the PIF looks at a quarterback's total “touches,” which includes passes, rushes, receptions and fumbles. Sacks, interceptions and touchdowns also go into the PIF formula, which should be seen as an average which is based on a 100-point scale for both the college and pro game. The PIF does not put a premium on long pass plays or passing yardage, but does penalize turnovers based on their frequency, not total number.

Going back to the Air Force-Hawaii game from 2012, Air Force quarterback Connor Dietz finished with a passer rating of zero because he didn't record any passing statistics. In his team’s 21-7 victory, Dietz did have 14 carries for 47 yards and was sacked only once, as the Falcons did not attempt a pass for the first time since 1992. Dietz's PIF number was a 92.9 for the game. The win put the Falcons into the Armed Forces Bowl. Air Force (which was the least experienced team in the FBS in 2012) also finished fourth in the Mountain West, which was two places higher than its predicted preseason consensus finish. Dietz finished 33rd in the country with a PIF of 56.8, behind Cody Fajardo (No. 15 in PIF at 63.6), Brett Smith (No. 27, 57.5), and Joe Southwick (No. 31, 57) in the Mountain West Conference.

In (then-) 22nd-ranked Texas Tech's double overtime victory (41-34) over Kansas last season, Seth Doege had a passer rating of 157.4 (out of college football's ridiculous' 1,261.6 max rating) for the Red Raiders. Meanwhile, his Jayhawk counterpart, Michael Cummings, had a 100.2 rating. Cummings, the redshirt freshman, was 6-of-15 for 29 yards with two touchdown passes to go along with 44 yards rushing on eight attempts (including two sacks). The gap in the passer ratings makes it seem clear that Doege, who completed 76.3 percent of his 59 passes and had a long pass of 31 yards, was more efficient than Cummings. Yet, what passer rating doesn't do is penalize turnovers enough, nor does it explain the threat Cummings presented.

Doege's lone interception of the game turned a 21-7 score into a 21-14 score five plays later. Cummings used his legs and threw a passing touchdown on the drive after the turnover. He also broke off a 44-yard run on an option keeper to set up the game-tying field goal to send the game to overtime. The Positive Impact Factor still gave Doege the edge at 66.4 to 60.9, but it suggests the play of the quarterbacks wasn't really as disparate as it seems. I would be remiss not to include the fact that the game-winning touchdown for Texas Tech was thrown by running back Eric Stephens from the wildcat.

While mobile quarterbacks did very well last season (Johnny Manziel, at No. 7 in PIF with a 66.6 rating, won the Heisman Trophy; Keenan Reynolds finished first for the regular season at 72.1), Eric Soza, J.W. Walsh and Colby Cameron all finished in the top 10 without reaching 100 carries (including sacks taken). More often than not, winning a national title need not involve a top 10 quarterback in PIF. However, teams did need a starter with an aggregate of around 50 or higher from 2000 through 2009. Alabama's A.J. McCarron was No. 25 last season with a PIF of 58.2 and was only the third national title-winning starter to finish below 50 since 2000. He finished at 47.9 during the Crimson Tide's 2011 title run. If McCarron is able to improve his PIF for a third consecutive season, it would be pretty hard to imagine Alabama not winning another title.