Yesterday, I noted one of the counter-intuitive facts of the 2017 season: the best defenses by yards per carry allowed weren’t very good teams, while the worst defenses by yards per carry allowed were good teams. The correlation coefficient between winning percentage and yards per carry allowed “should” be negative, but was in fact a positive 0.37.
What about for offenses? Well, the correlation coefficient is a positive 0.26, which is more intuitive. It means the teams that average more yards per carry also average more wins, although the relationship isn’t particularly strong. The best 8 teams by YPC average have won 54% of their games, while the worst 8 teams have won 45% of their games. The Steelers are a noteworthy example, as Pittsburgh is 11-2 but ranks 28th in yards per carry. The Bears and Browns rank 5th and 7th in yards per carry, but have combined to go 4-22.
But in general, there is a positive correlation in 2017 between being good at gaining yards per rush and winning teams. So the “reasons” you may have used to justify why bad teams were good at yards per carry allowed don’t hold much water here.
Behind Mark Ingram and Alvin Kamara, the Saints lead the NFL in yards per rush and are one of the top teams. The Eagles have LeGarrette Blount and Jay Ajayi to thank for helping Philadelphia rank 4th in YPC and boast the best winning percentage in the NFL. The chart indicates a weak but positive relationship between team success and yards per carry.
Of course, this is only for one season. So let me ask you: what do you think explains the difference between offensive and defensive yards per carry and the correlation with winning? And what will it look like when we compare to prior seasons?