≡ Menu

Foster is thankful for a heavy workload.

Foster is thankful for a heavy workload.

Running back workload is a very difficult topic to tackle, and I don’t expect to make much of an indent into the subject today. But I do want to take a few minutes and look at some ways to measure heavy workloads. One school of thought is that the effect of carries is cumulative: Not only is a 25-carry game more likely to cause a running back trouble than a five-carry game, but it’s more than five times as likely to shorten a player’s shelf life. The cumulative effect of taking hit after hit means that carries 16, 17, and 18 hurt a runner more than carries 1, 2, and 3.

I don’t know if that’s true, but let’s investigate. First, I’m only giving a running back credit for his additional carries after his 15th carry of the game. So an 18-carry game goes down as a “3” and a 25 carry game is a “10.” Using this scoring system, Arian Foster had the highest number of “Carries over 15” from last season, with 117. Such a list mostly corresponds to the number of overall rushing attempts for a player, but the exceptions could be revealing.

Foster led the league in both carries and carries above fifteen. But Darren McFadden ranks pretty high on this list thanks to three games with 27+ carries. On the other hand, Stevan Ridley ranked 6th in carries, but he only had one game with more than 22 rushes. McFadden had a 27-carry game in week 6, a 19-carry game in week 7, and a 29-carry game in week 8; in week 9, he injured his ankle and missed a month. Ridley, on the other hand, seemed to be handled pretty well, and one might argue that sharing time with Shane Vereen is good for his long-term health.

We can also use this “Carries over 15” statistic to get a sense of how teams’ commitment to the running back-by-committee philosophy has waxed and waned over the years. I totaled the number of “Carries over 15” for the top ten leaders in that statistic every year since the merger. The values themselves [1]Note: I pro-rated all non-16 game seasons to 16-games. carry no intuitive meaning, but the relative shape of the curve tells us all we need to know:

car over 15

Contrary to popular belief, RBBC was very high in the early ’70s, and the “stud running back era” peaked in the early part of last decade (this is the sort of thing Doug, Jason, Neil and I used to write about at the PFR Blog).

But over the last few years, RBBC has clearly impacted the league: there has been a significant decline in the number of over high-carry games by top running backs. The number of high-carry games simply isn’t what it was at its peak a decade ago. Foster appears to be an exception, although he can’t touch some of the old numbers (presented at the end of this post). Some have attributed Foster’s declining declining yards-per-carry average to his heavy workload, an idea I addressed here.

But do these high-carry games lead to injury? I looked at the 583 running backs since 1970 to record 200 carries for a team in one season, and then play again for that team in the following season. I thought maybe we’d find some injury evidence indicating that high-carry games lead to missed games the following season. The second-highest season (with a “Carries over 15” score of 172) belonged to Jamal Anderson in 1998, who played in just two games the next year. And three others in the top ten (Barry Foster ’92, Terrell Davis ’98, and Edgerrin James ’00) also missed significant time the next year.

But that’s misleading. For one, the rest of the top ten remained healthy the next year. In my sample of 583 backs, I broke them down into five groups: the 50 highest backs (in terms of carries over 15), the next 100, the middle set of 283 running backs, the next 100, and the 50 lowest backs. As you can see, it doesn’t seem like the workhorse backs were more likely to get hurt the following year.

Anyway, this is just one data point. I hope to look into the issue more over the next few months (or more likely, few years). Finally, I will close with a list of the single-season leaders in “Carries over 15.”

Seeing George atop the list is no surprise in light of one of the craziest stats I’ve ever come across: he had 519 carries during the 2000 calendar year.

Previous “Random Perspective On” Articles:
AFC East: Buffalo Bills, Miami Dolphins, New England Patriots, New York Jets
AFC North: Baltimore Ravens, Cincinnati Bengals, Cleveland Browns, Pittsburgh Steelers
AFC South: Houston Texans, Indianapolis Colts, Jacksonville Jaguars, Tennessee Titans
AFC West: Denver Broncos, Kansas City Chiefs, Oakland Raiders, San Diego Chargers
NFC East: Dallas Cowboys, New York Giants, Philadelphia Eagles, Washington Redskins
NFC North: Chicago Bears, Detroit Lions, Green Bay Packers, Minnesota Vikings
NFC South: Atlanta Falcons, Carolina Panthers, New Orleans Saints, Tampa Bay Buccaneers
NFC West: Arizona Cardinals, San Francisco 49ers, Seattle Seahawks, St. Louis Rams

References

References
1 Note: I pro-rated all non-16 game seasons to 16-games.
{ 4 comments }