Is passing or running more correlated with success in college football?

Near the end of the 2012 college football season, I got a little bored in my Federal Income Tax class, so I decided to run some regressions to determine whether a good passing game or a good running game had a stronger correlation to success (points scored and games won). What I learned was a little surprising.* I learned that a team’s rushing yards per game has a higher correlation than the team’s passing yards per game with (1) scoring points and (2) winning. Despite the popular belief that modern college football is all about the passing game, a good running game is more likely to lead to success.

That was the sparknotes version of the research; bear with me if you want more of the details.
Here’s the correlation and statistical significance breakdown of six of the regressions I ran:

  1. Pass yards-Points R squared=.22 (statistically significant)
  2. Rush yards-Points R squared=.31 (statistically significant)
  3. Pass yards-Wins R squared=.03 (not statistically significant)
  4. Rush yards-Wins R squared= .21 (statistically significant)
  5. Total yards-Wins R squared=.28 (statistically significant)
  6. Points-Wins R squared=.52 (statistically significant

Look at that difference in R squared between pass yards-wins and rush yards-wins. Rushing yards per game (ypg) can explain 21% of a team’s win total while passing ypg can only explain 3% of a team’s win total. If you knew nothing about a team except how many ypg the team rushes, you should have a hazy idea of how many wins the team will accrue. If you knew nothing about a team except how many ypg the team passes, you might as well just guess a random number if you’re trying to predict how many wins the team has.

Now look at the difference in R squared between total yards-wins and points-wins. Unsurprisingly, scoring points is a much better indicator of winning that gaining yards. This affirms the importance of a good red zone offense. Running up and down the field won’t do you much good unless you can convert those yards to points. (I was also interested to see that the R-squared for points-wins was so close to .5. I’m guessing that if I ran a points allowed-wins regression, the R-squared would be very close to .48. If this is true, it would suggest that scoring and stopping the other team from scoring are nearly equal in importance to winning)

By looking at the coefficients of each regression, we can learn a few more interesting facts. 

  1. If Team A has 40 more total ypg than Team B, Team A is expected to win one more game than Team B (during a 12 game regular season schedule).
  2. If Team A has 40 more rushing ypg than Team B, Team A is expected to win one more game than Team B.
  3. If Team A has 118 more passing ypg than Team B, Team A is expected to win one more game than Team B
  4. If Team A scores 4 more points per game (ppg) than Team B, Team A is expected to win one more game than Team B
  5. If Team A has 10 more ypg than Team B, Team A is expected to score 1 more ppg.
  6. If Team A has 12 more ypg than Team B, Team A is expected to score 1 more ppg.
  7. If Team A has 16 more ypg than Team B, Team A is expected to score 1 more ppg.

These facts only show correlation, not causation, but they suggest that a team hoping to improve its offense should focus on the running game rather than the passing game. I think that point 4 is intriguing. It suggests that (all else being equal) a team that hopes to improve its record will need to improve its offense by 4 ppg for every additional win the team hopes to achieve.

Next time you hear a football analyst proclaim that college football is all about the passing attack, just remember that rushing yards are still far more indicative of how well a team is playing.

*It was surprising to me, at least. My friend, Barry, responded to my research by saying “this fact is a little obvious. Teams that can run are more likely to win because they are more likely to have a two-dimensional offense. They are more likely to have the ball longer. Also, teams pass more to catch up when they’re losing and run more when they’re winning to run out the clock. Any way you put it, running the ball is important.” Barry and I disagree about how surprising my result was, but I think his analysis is a good explanation for why the running game is still important in football. 

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