This guy basically ripped off Football Outsiders and didn't even properly state the idea here.
A running back with a season of 370+ carries will almost always decline afterward, and the effects get worse as the carries on that season increase. Except Eric Dickerson and LT...and the funny thing is, they just recently figured out the exact reason why that is. It's something a lot of "purists" can't stand: Ducking out of bounds.
Dickerson, of course, was hated by the media throughout his career for doing just that. And, in studying game logs, the crew at FO learned that LT goes out of bounds more often than any other RB today. Actually, it was Emmitt Smith who told him to start doing this; Smith's own decline began after two 370+ carry seasons. Looking at the out-of-bounds data for all RBs suggests that this is indeed effective in extending careers.
LJ, on the other hand, does not shy away from contact. He specifically prides himself on being "tough" and "physical" IIRC. This, combined with his record-setting workload last season, is why I will not own him in any fantasy league this year and why nobody in their right mind should trade for him IMO.
-Josh