Adrian Peterson is adjusting to the Minnesota Vikings' offense instead of carrying it. Marshawn Lynch and Eddie Lacy rank second on their own teams in rushing. DeMarco Murray's per-game rushing production has fallen by 56.3 percent from last season. Jeremy Hill and C.J. Anderson rank outside the top 35 in rushing after filling the top two spots over the final eight weeks of 2014. Worse, Jamaal Charles and Arian Foster have suffered season-ending injuries.
Oh, and just in case this new NFL landscape at running back wasn't disorienting enough, the Atlanta Falcons' Devonta Freeman is the league's leading rusher -- just ahead of Chris Johnson and Doug Martin. Those three combined for 1,845 yards rushing last season -- less than Murray's NFL-best 1,875.
What follows is my attempt at capturing a snapshot of the new and evolving running back hierarchy. The goal was to balance established track records with projected career trajectories, using input from coaches and evaluators who are themselves still making sense of all the changes.
1. Le'Veon Bell, Pittsburgh Steelers
A two-game suspension cut into Bell's numbers, but he remains a frequent choice as the NFL's best back. He has tremendous size for the position at 6-foot-1 and 244 pounds. He has breakaway speed and the versatility to excel as a runner, receiver and pass protector. "You have to put Bell at No. 1," a personnel director said. "He is a pretty special guy. He can create. He doesn't need a point of entry like a lot of guys do."