Pac-12 Networks' Mike Yam, Curtis Conway and Nigel Burton discuss their current favorites for the Heisman Trophy and why Stanford's Christian McCaffrey is separating himself from the field thanks to his unique skill set. See more editions of "Nissan Heisman Watch" on Tuesday nights during "Inside Pac-12 Football" at 8 p,m. PT/9 p.m. MT on Pac-12 Network.