This may not necessarily be a bug, but it doesn't seem to be working properly. In one of my recent games, my QB did maybe like 20 quick reads cause the opponent kept using the same defensive plays. I don't have the exact stats, but it seemed like he went under 50% on those passes. I feel like if a QB decides to do a quick read/pass, the receiver should be relatively open, not just force a throw in because he recognizes the defensive play. It's as if the QB makes the assumption that a receiver will be open without actually verifying it with his eyes.
