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Fantasy: Running Back Workload (FBG)

Over at Footballguys.com, I try to unravel the relationship between workload and age. Eight years ago, Doug wrote three articles on the topic; sadly, I’m not sure we’ve come very far since then. So I decided to at least begin the process of measuring how much of an impact “mileage” really has on running backs.

Conventional wisdom suggests that, all else being equal, running backs with “low mileage” are more likely to age gracefully than running backs who have accumulated a significant number of carries.

This, unfortunately, is a very complicated issue to test. For example, new Giants running back Rashad Jennings is 29 years old, but he has just 387 career carries.  This makes Jennings a “young” 29, but is that better than being an “old” 28? The best way to test this question is to analyze running backs of similar quality as Jennings — but who had a lot of carries by the time they were 28 years old — and see how the rest of their careers unfolded.  The problem is that the list of running backs with a lot of carries through their age 28 season bear no resemblance to Jennings. The players with the most carries through age 28 are Emmitt Smith, Edgerrin James, Jerome Bettis, Barry Sanders, LaDainian Tomlinson, Curtis Martin, and Walter Payton, which basically serves as a who’s who of running backs who are not comparable to Rashad Jennings.

Generally speaking, the best running backs get the most carries: did you know that Jim Brown is the only player to lead the NFL in carries more than 4 times? He did it six times in his nine-year career. Along the same line of thinking, the running backs with the most carries are generally among the best running backs.  Running backs who haven’t had a lot of carries through age 28 generally either aren’t very good or have suffered multiple injuries, which makes it tough to find players who feel like true comparables to a player like Jennings.

One could argue that running back workload and running back quality are so inextricably tied that it’s impossible to accurately measure whether age or workload is more important.  But today, I want to take a step back from examining the specifics of a player like Jennings and look at the big picture.  There are some examples that appear to support the “running back mileage” theory.  Shaun Alexander had a significant number of carries through age 28, and was excellent at age 28; the fact that he then declined so significantly, so quickly, could be a sign that workload really mattered. After all, few players suffer such sharp declines when turning 29. But that’s just one data point.  What if we can bring in many more?

You can read the full article here.

  • Nick Bradley

    Just read the article — great!

    Two questions:

    1. have you considered throwing RB weight into your multivariate regression? a priori I’d think that workload is a bigger factor for bigger backs (joints, injuries, etc).

    2. where can I convert VBD to rushing yards?

  • Jeremy Crowhurst

    Shaun Alexander is probably the worst example you could have thought of for “running back overuse”. Alexander was a selfish, narcissistic player whose production dried up because he didn’t care about football. Once he got his record, and got paid, his decline was eminently predictable to anyone who’d witnessed his time with the Seahawks, in particular his sideline hissy-fit the year before when his coach chose to take the win over celebrating the greater glory of Shaun.

    I appreciate the desire to mine trends from numbers, but when explanations are there in the circumstances, I think I have to give you a wag of the finger. It really is almost as bad as Football Outsiders famous Curse of 365 — all running backs who have 365 or more carries in a season suffer a serious decline in production the following year, unless their name is Eric Dickerson. Or Earl Campbell. Or Emmitt Smith, Curtis Martin, Edgerrin James, Terrell Davis, Walter Payton, or LaDainian Tomlinson.

    Okay, so I’ve done a bit of an edit on their rule, but I think my version captures an essential truth that theirs overlooks. There’s a reality to peak production in professional sports. In order to perform at a Hall of Fame level over multiple seasons, a player needs to have a Hall of Fame work ethic. As a player gets older, it takes greater effort in the off-season to get the body in the kind of shape it needs to be in to produce at an elite level. When you look at the list of one or two-year wonders, what you see is a list of players with drug problems, players with attitude problems, and occasionally, players with injury problems. (Marcus Allen’s ankle injury in week three of 1986 after being gang-tackled by the Giants defenders being a classic example.) The Shaun Alexanders and Larry Johnsons of the NFL had what it took to climb the mountain, and they had what it took to stay on the mountain long enough to cash the big paycheck. But they didn’t have what it took to stay there.

    • Nick Bradley

      Great point — many of the great backs had an amazing work ethic and had longer careers.

      …but about Tomlinson? Based on character and work ethic, he should have played longer. Emmett Smith played 15 seasons, Tomlinson 11. Interesting to note: identical CarAV.

      • Jeremy Crowhurst

        Yeah, that’s true. Everyone is different, and there comes a point where the body is just no longer willing. Guys like Emmitt and Marcus Allen and Walter were able to play at a high level relatively late. Others, like LT and Curtis Martin and Thurman Thomas, would still be playing if their bodies would just let them.