By definition, you can't measure explosiveness, lateral instincts, awareness etc. Not in terms of football stats anyway.

Another part of analyzing the empirical data is the lack of context. Henderson's overall numbers look impressive enough but does anyone really think they would apply if it was at the goal line on 4th down? IMO, he is a decent enough between the 20's RB but he isn't that next level RB that can generally get you the crunch time stuff.