Before I move on from my yards before contact research to a more comprehensive evaluation of the difficulty of running back attempts, I wanted to spend a bit more time with the differences teams can see. Previously, I found that an adjustment to yards before contact per attempt to cap individual plays at 5 yards before contact better aligns the metric with blocking quality rather than rushing quality. But when the Panthers became one of the biggest movers in estimated line play with that adjustment, I wondered if there was more to the story. It turns out that individual players on the same team can have dramatic differences in their average yards before contact and even different distributions of similar averages can influence a rusher’s success.
Like many football statistics, yards before contact are not normally distributed. It looks pretty normal with a median between 0 and 1 yard past the line of scrimmage, but breakaway runs produce a long tail with sporadic plays with more than 5 yards before contact. Once the back clears the first level, the point of first contact is frequently determined by where the play started — are there 80 yards until the end zone or just 10 — and by the speed and elusiveness of the back. In a chart of the distribution of yards before contact from last season, I folded all of those longer runs into one bucket of plays with 5 or more yards before contact. Those accounted for a bit less than 14 percent of all attempts.