Size does seem to be a part of the definition, but the only succesful "scat backs" I've seen at OSU in the last few years would seem to me to be Archie, Carlos Snow, Peppy Pearson and Michael Wiley (you could possibly add MoC to the list) All three had an ability to run between the tackels, go wide, and be the outlet receiver. All three possessed great balance to go along with speed and stength. AND only one, MoC played for Tressel and Bollman and he played as a freshman on what was still mostly a Cooper recruited team.
So how is it that Mike Hart and Jevon Ringer can make it as scat backs on teams with less talent and it takes a Beanie or a Pittman to get any kind of yardage. Is it the blocking style? Is it a different offense? I could understand if there had been some adequate back ups, but for three years in a row the Buckeyes couldn't run dick until Pittman stepped up and it wasn't until the middle of the season that Boom could be counted on to back up Beanie. It just doesn't make sense to me on a team with as much talent up front.