Pac-12 Networks' Mike Yam, Curtis Conway and Nigel Burton talk some early Heisman hopefuls after four weeks of the college football season. A slew of running backs dominate the early notables, with LSU's Leonard Fournette leading a pack that includes Utah's Devontae Booker and UCLA's Paul Perkins. Catch more "Nissan Heisman Watch" analysis each week as part of "Inside Pac-12 Football: Digital Edition."