Mark Ingram clearly the top RB

Alabama's Mark Ingram is the only legitimate first-round running back prospect in the 2011 NFL draft, and even he has some detractors who point to durability issues and lack of top-notch acceleration as buyer-beware signs.

There is more depth in this year's class than in recent years (with the notable exception of the 2008 class that produced eight of the NFL's top 16 rushers in 2010), but durability concerns and size limitations are the two prominent red flags that teams must sort through when stacking this year's running backs board.