Spiller is one of the most physically gifted backs in the league. He's yet to prove he can move the chains consistently by running between the tackles. I'm giving him a pass for last year's high-ankle sprain. ... What percentage of Morris' effectiveness to date is due to a gimmick offense and the dual threat of Robert Griffin III? In games featuring at least 20 pass attempts by Kirk Cousins, Morris has averaged nearly a full yard less (3.94) than his career mark (4.85) with RGIII under center. Morris is also a non-factor as a receiver in an increasingly pass-heavy league. ... We don't put much stock in preseason results, but we do look for traits. Ingram was the most impressive back I saw last month, breaking off 10- to 15-yard runs where previously he would have been stopped near the line of scrimmage. He's poised to emulate Ryan Mathews' 2013 breakout season in an offense with record-breaking potential.