I've always been impressed by Sankey's ability to pick out running lanes, even with our shitshow of an OL. I think they call that vision or something.
Sankey creates his own running lanes by setting tacklers up. He sees the entire defense and looks like he has a plan for how to beat it before he gets the ball. He's working on setting up the second level while still juking the first guy through...and there's almost always a first level guy through. This is why he's better than Polk. Polk was all brawn and burst but often ran into tacklers that he could have avoided. His gift was the ability to take a solid hit and keep running. Sankey runs smart and avoids those hits.