A few years ago, Football Outsiders concluded based on historical data that backs who eclipsed the the 370-carry mark are especially prone to break down the following season. While it makes sense generally that heavy workloads would tend to wear players down, it doesn't follow that any one cutoff point (300, 350, 370, etc.) would have any special significance given the diversity of running-back body types, blocking schemes and running styles. Nonetheless, the 370-rule gained some traction, and some owners have avoided these 370-plus backs (Michael Turner is the only one from last season). Are they wise to do so? Not according to analysis by Advanced NFL Stats which explains the 370 curse as garden-variety regression to the mean, normal running back injury rates and some cherry-picking of stats. (h/t: Yahoo! Sports' Scott Pianowski and Andy Behrens).

It's worth clicking through the link, but the explanation is fairly obvious. When a back gets the ball 370 times, he's necessarily healthy all year, almost always near his peak in production (why else give him the ball so much) and playing on a team that's often winning late in games. When those (and a couple other factors) don't align perfectly - and they rarely will - the back will see less carries, be less effective, or miss time due to injury. In fact, no matter what kind of season a player has the year before, he's very unlikely to do as well as the typical 370-carry back in the succeeding one.

Again, I'm not necessarily denying the relationship between workload and decline, but I'd expect it depends on a lot of factors, including genetics, running style, career workload, etc. In other words, there's no reason to think Michael Turner (377 carries) is a bigger risk than Matt Forte (315 carries) or Adrian Peterson (364 carries) based merely on Turner's passing a magic number.