I did a little research on ProFootballFocus, now that they've got their wk 17 stats included, with a view to comparing the Yards Gained After Contact that various RBs in the league have amassed.
Jonathan Stewart has amassed 740 of his 1133 yards this season AFTER initial contact, or 65.3% of his yardage.
Only 3 backs that I could find did slightly better: Stephen Jackson of the Rams (954 of 1422, or 67.8%), Maurice Jones-Drew of the Jags (930 of 1391, or 66.8%), and AP of the Vikes (915 of 1394, or 65.6%).
Marion Barber was 63.9, Ryan Grant was 61.8, Jamaal Charles was 61.3, Ray Rice was 54.4, and Thomas Jones was only 49.8% -- our DeAngelo Williams was 56.8, lower than I'd thought.
What does this mean? Make your own judgment, but I think it identifies the guys who can move the chains on their own, and who don't depend as much on the holes that their OLmen give them. Congrats to Jonathan on coming up big the last 3 games, when he got his chance to be the feature back for us -- and beware of too much trade talk for him -- he's just too good to let go, IMO.