Referendum, I'm sure that statistic is out there, though it may have to be found on a team by team basis. I'm seen many white receivers have bad drops, but I've never seen a white receiver or tight end with consistently bad hands like we find in a large number of black receivers and tight ends.
With quarterbacks, there's so much statistical data, plus the importance of the quarterback in a team's success or failure can't be nearly as easily hidden as with other positions. But never underestimate the tendencyof football coaches to be Caste System copycats. What else explains the blind allegiance toimmobile sumo linemen, receivers that can't run routes or catch, running backs that are slow or run out of bounds to avoid contact, not to mention the large number of downright lousy defensive players? And oh yeah, the huge number of thugs, criminals, and incredibly selfish players in general. The Caste System runs strong and deep and many coaches will continue to try to field a black quarterback whenever possible, though a few are shrewd enough to always keep the starter and backups white.