ESPN's annual poll ranking the non-rookie quarterbacks in the NFL dropped this week, and Cowboys' starter Dak Prescott didn't even crack the top 10.In fact, Prescott was placed in the third possible tier, with the fourth tier being the lowest.What does all of that mean?Tier 1 is reserved for quarterbacks who can "carry their team each week" and can "expertly handle pure-pass situations." Tier 2 is for QBs who can "sometimes carry a team" but have "a hole or two" in their game.Tier 3, Prescott's tier, is for QBs who "need heavier run games and/or defense to win" and have a lighter load because of "lower-volume pass offenses."That description, to be honest, sounds like Dak.