Not All RBs Embracing NFL's Shift Away From Power Run Game

PHILADELPHIA — Adrian Peterson struggled with a new system, so he got what he wanted. DeMarco Murray had trouble in a different offense, so he was benched.

More NFL teams are running the ball out of shotgun and pistol formations instead of an I-formation or a split-back set. Power football has become more old-fashioned than old school.

It's been a tough trend for some of the league's elite running backs.

After missing nearly the entire 2014 season, Peterson returned to the Minnesota Vikings and found the team operating much of its offense with quarterback Teddy Bridgewater in the shotgun. Peterson wasn't comfortable getting carries without a full head of steam. He said he was "hesitant"…