Don’t disagree with Shanahan’s wording about “finding creases”. Also believe it’s dismissive to hang your hat on height/weight measurables to determine a players potential to be an effective short yardage back.
If you’ve spent time with gym rat meat-heads, you’d know that the dude you can’t knock off balance is the guy with the lower center of gravity that squats 500+. They also have the advantage in terms of short space agility which helps locate creases and accelerate through them.
Lots of mention of Bettis, probably do to his physical presence but the guy operated with footwork similar to that of a lightweight boxer. Extremely rare for a dude of his girth.
I do believe Zeke had a knack of locating creases and just eking-out enough yardage on many occasions. I will side with those that say it wasn’t necessarily punishing runs, though. As his physical skills eroded, he had to play with more intelligence. To those the say Zeke apologists (I’m not) hang their hat on his blocking, you do realize it is a passing league, right? Pollard just may get Tat-leg killed, or you’re going to see a lot of Ronald Jones on 3rd downs.