Predicting Success in the National Football League
An in-depth look at the factors that differentiate the winning teams from the
losing teams.
Benjamin RollinsCenter for Quality and Applied StatisticsRochester Institute of [email protected]
Why NFL?• Many theories as to optimal style• The year of the quarterback vs. ground and
pound style• Third-down conversion is always thought to be
important, but is it? Also, is it the most important?
Data• Game by game for seasons 2000 to 2012• 13 variables per team
• Start with analyzing just 2012
Score
Rush Yards Pass Attempts Pass Completions
Pass Yards
Interceptions Fumbles # of Sacks Sack Yards
Penalty Yards First Downs Third Down % Rush Attempts
Game by Game• Summaries of the season data do not fully
capture what we want to show.• Each game is unique• Use difference of variables
http://www.thepigskinreport.com/2013/02/new-york-giants-team-needs-in-the-2013-nfl-draft/
Regression• Regression Analysis: A statistical technique for finding the relationship between one or more predictor variables (
Linear ModelCoefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 0.04956 0.87032 0.057 0.955 ThirdDown% 0.38662 0.04362 8.864 <2e-16 ***---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 13.88 on 254 degrees of freedomMultiple R-squared: 0.2362, Adjusted R-squared: 0.2332 F-statistic: 78.56 on 1 and 254 DF, p-value: < 2.2e-16
• Multicollinearity?
Is it in the reduced model?
Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 0.152902 0.409829 0.373 0.709405 FirstDownDiff 1.159401 0.112056 10.347 < 2e-16 ***ThirdDownPctDiff 0.138390 0.026109 5.300 2.57e-07 ***RushAttDiff -0.310206 0.064477 -4.811 2.62e-06 ***PassAttDiff -0.694839 0.055680 -12.479 < 2e-16 ***PassYdsDiff 0.038643 0.006915 5.588 6.08e-08 ***PassIntDiff -3.708635 0.323783 -11.454 < 2e-16 ***FumblesDiff -3.507530 0.345547 -10.151 < 2e-16 ***SackNumDiff -1.146368 0.176320 -6.502 4.39e-10 ***PenYdsDiff -0.044011 0.013103 -3.359 0.000907 ***---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 6.333 on 246 degrees of freedomMultiple R-squared: 0.8459, Adjusted R-squared: 0.8403 F-statistic: 150.1 on 9 and 246 DF, p-value: < 2.2e-16
Is there a better response?
• Is score difference our true goal?
http://www.lakehighlandstoday.com/index.php/sports/article2/wildcats_open_district_play_with_big_win/P9/
Response of win• Most games in the NFL are close• The result of the game is much more important• Binary
Logistic RegressionCoefficients: Estimate Std. Error z value Pr(>|z|) (Intercept) -0.237213 0.228341 -1.039 0.298873 FirstDownDiff 0.204891 0.050074 4.092 0.00004280388 ***ThirdDownPctDiff 0.044233 0.014299 3.093 0.001979 ** PassAttDiff -0.199615 0.034758 -5.743 0.00000000931 ***PassYdsDiff 0.016293 0.004253 3.831 0.000127 ***PassIntDiff -0.920326 0.209554 -4.392 0.00001123954 ***FumblesDiff -1.176667 0.280184 -4.200 0.00002673654 ***PenYdsDiff -0.026114 0.007237 -3.609 0.000308 ***---Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
(Dispersion parameter for binomial family taken to be 1)
Null deviance: 354.88 on 255 degrees of freedomResidual deviance: 129.69 on 248 degrees of freedomAIC: 145.69
Interpretation• For Third down conversion percentage
• Increasing your Third down conversion percentage by 1 results in about a 5% better chance to win the game.
How good is this model?
Full Predicted
Actual Loss Win
Loss 113 16
Win 9 118
Overall error: 0.09766
Test Predicted
Actual Loss Win
Loss 18 4
Win 3 14
Overall error: 0.17949
Conclusion• Rush attempts is a very important variable in
predicting the result of an NFL game.• Third down conversion percentage is important as
well.• Less mistakes, more carries and a better third
down conversion percentage usually results in a better team.
http://espn.go.com/blog/nflnation/post/_/id/68692/mvp-watch-what-about-adrian-peterson
Questions?
• Data Sourceo http://www.repole.com/sun4cast/data.html
• Benjamin RollinsCenter for Quality and Applied StatisticsRochester Institute of [email protected]