NFL Combine 2013: Running back drills

When it comes to running backs, cutting and explosiveness are key.

At the NFL Combine, rarely does a running back not get tested in either area in any drill. The featured drill at NFL.com is the "off-tackle reaction drill", and it combines both.

In this drill, the running back takes a hand-off from a coach and swoops around a set of cones. He then runs through a set of bags before meeting up with a coach holding a bag vertically. The coach will swing the bag left or right. Whichever way the coach moves the bag, the running back has to cut the other way at virtually full speed. The running back then hooks around a cone and then accelerates up the field to finish the drill.

It's critical that the running back keeps his eye on the coach so he can cut the right way as quickly as possible. Coaches will look for the running back to make a solid plant and move up the field.

Players to watch

--Eddie Lacy, Alabama -- Lacy will face plenty of questions after running behind the best offensive line in recent college history, but don't sell him short. He has good vision, cutback skills and a second-level burst, and is one of the more polished runners in a weak class. He's one of the few incoming rookies I can see as a Week 1 starter.

--Giovani Bernard, North Carolina -- Bernard has impressive burst and agility, but he is tentative running between the tackles, more content to dance behind the line looking for a hole than just running forward. A good talent, but these questions linger over him.

--Joseph Randle, Oklahoma State -- Randle fits the mold of a lot of guys in this year's class -- he has good cutback skills and can make defenders miss in the open field, but struggles between the tackles and is too eager to run to the sidelines looking for a hole that isn't there.