[funman]

Routes run against zone defenses can be designed to have the receiver settle in a opening between LBs and DBs. The QB gets the ball into the opening and to the receiver faster than the defender can react to the ball. If you see a QB miss a stationary receiver against a zone, it could be because the receiver didn't settle in the spot that allowed a throwing lane for the ball. The receiver and QB must reaad the defense the same way.

Against man to man defenses the receiver is being thrown to on the move at a point where a feint or a cut creates separation between the receiver and defender. If a QB throws a fade route to the back pylon of the end zone and a CB in man to man knocks the receiver out of his route at the LOS, the receiver will not be able to get the back corner on time and the ball will appear to be overthrown.