Yards per carry are a terrible way to measure the contribution of a running back.
I have been saying this all along, haven't I?
http://www.footballperspective.com/t...rds-per-carry/
Chase Stuart
One way to look at this is to say that carries are king; like routes run, they represent opportunities given to a player, which is a strong indicator of talent. Another interpretation is that YPC is a fickle mistress. It is extremely sensitive to outliers, and two or three carries can completely skew a player’s production. I’m not telling you anything you didn’t already know, but the data here seems overwhelming to me.