The best NFL running backs can change direction in a blink.
But this is the kind of directional change that would have a coach swallowing his whistle: Buffalo's LeSean McCoy is the only one of last season's top 10 rushers who currently ranks among this year's top 10, and he's hobbling around on a bum knee.
Remember how 2014 rushing champion DeMarco Murray was going to tear it up in Philadelphia? He's been a bust.
Seattle's Marshawn Lynch is hurt and hasn't played since mid-November, and long since done for the season are Pittsburgh's Le'Veon Bell and...