The QB position obviously is unique, but the point remains: Outside circumstances as much as talent level or draft status dictates how soon a rookie is called on in the pros. The Broncos agreed to trade for Joe Flacco more than two months before the opportunity to trade down with Pittsburgh in Round 1 for an extra second-rounder converged with Lock's surprising tumble to Day 2. Arizona doesn't draft Murray No. 1 overall, and Washington might not pick Haskins, if not for the Kliff Kingsbury hire and Alex Smith injury, respectively.
The NFL is a league about attrition and turnover, where patience decreasingly is awarded.