Charles is a boom-or-bust back in the fashion of Johnson, but he hits the hole more decisively than Johnson at this stage of their respective careers. When the Chiefs feed him, he's money. Chip Kelly's run-dependent offense remains largely under wraps, but McCoy's skill set should be ideally suited to the track-meet tempo. The severe concussion that sidelined Shady for a month late last season is more than slightly disconcerting. Richardson gets high marks for playing through knee soreness and broken ribs that were so painful he had to sleep upright. He's a better talent than fellow second-year pros Martin and Alfred Morris.