I disagree. Grigsby gained most of his yards on a couple long runs where he ran through gigantic holes and no one touched him. Those plays were made by good blocking, not by Grigsby. I swear half the people on this forum could have made that touchdown run up the middle. There were also at least 2 other 15 yard runs in the 4th quarter where he went untouched until well into the secondary. On those runs it doesn't really matter who the running back is, nearly any pro RB could have made the exact same run.
I still don't remember the last time I saw Grigsby actually make someone miss, or break a tackle. He seems capable of running through holes at a decent rate of speed, but that's about it. He isn't anything close to elusive, or physical.
Cotton hasn't had nearly the same opportunity, but does look more explosive. I'm not sure either is the answer. Our O-Line is weak, we need a running back that can either make people miss, or break a lot of tackles.
I miss Chris Garret. Before his injury he was awesome. Fast, physical, and no nonsense. One cut and go full tilt, we need someone like that again.