Very simple drill, OL begins in stance, he will execute a quick set on cadence and "get his feet hot". On my whistle the "defender" will move around, the OL must work his feet and "mirror" the defender so that he is always splitting his crotch.
It reinforces good stances, quick sets, good anchor position and body position, keeping feet hot, proper stagger, stepping while not hopping, and staying in front of the defender.
When we get pads on the defender will rush the OL at the end of the drill and they have to drop their butts and punch. If they get lazy on their sets I stop and make them start over.
Here is some video I had a kid shoot today with my Iphone.
First group the kid on the left is doing some crazy rocking thing with his hands, ignore that. The 2 kids in the second group are much better, the one on the left is my graduating 1st team all league RT/DE (he works out with us some days) and the kid on the right started at Center as a sophomore this year, should be very good for us the next 2 seasons.