Pac-12 Networks' Mike Yam, Curtis Conway and Matt Leinart discuss their current favorites for the Heisman Trophy and why Stanford's Christian McCaffrey is using his versatility to separate himself from the pack. 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.