Running back is one of the toughest positions to draft in fantasy football.
Ballcarriers nearly always take a pounding with every touch, and the beatings wear them down faster than most other positions in the NFL. According to a study conducted by Dartmouth University (reported through FootballGuys.com), the average career span of the position is 4.35 years, which is shorter than any other position in football.
With halfbacks' careers lasting only a few years (and their productive peaks being even shorter), it's nearly impossible to predict the top fantasy runners, even on a year-to-year basis.
All it takes is a look at RBs Chris Johnson and Adrian Peterson, the two top running backs just a couple years ago, both of whom suffered major drops in production at 2011 (Peterson ended up tearing his ACL in Week 16).
The RB position in fantasy football is a lot like the closer position in fantasy baseball: It's almost impossible to know where elite production will come from entering any given season, so it's best not to waste a high pick on a less-than-sure thing.
Instead, let's take a look at five running backs with tremendous upside that should be available late in your fantasy draft.