You know the big names that will shape playoff games over the next three weekends leading to the Super Bowl -- guys like Tom Brady, Peyton Manning, Matt Ryan and more. The list below, by conference, features four players on each playoff-bound team who could shake up how a wild card, divisional or conference championship contest is decided. They are playoff "X factors."
RB Danny Woodhead: He is surprisingly tough and elusive as a runner. His size allows him to "hide" behind that offensive line. As a receiver, no matter where (slot, outlet, etc.), he can be dangerous.