The Tampa Bay Buccaneers have a pretty iffy group of running backs, but the backs they do have are pretty good at one thing: catching the football. In looking at first-down conversions after the catch, Pro Football Focus named Bobby Rainey one of the most efficient backs in the NFL.
According to Pro Football Focus, Bobby Rainey converted 14 of his 33 opportunities into first downs, which ranked fourth in the NFL. That's a fairly small sample, of course, but it fits the film and the production: 33 catches for 315 yards and a touchdown is pretty good for a running back, especially one who started just five games.