Zone Alert Bubble

Key the alert defender, usually the flat corner or overhang linebacker, since his run fit versus flat drop determines whether you hand off or throw the bubble. Watch for a defender sitting in the bubble screen lane pre-snap, since a user-controlled lurk defender there can jump the throw and blow up the RPO. Zone coverages with soft corners are more vulnerable to the bubble since the flat defender has to respect run first, then react late to the screen. Man coverage with a corner pressed on the slot receiver can undercut the bubble route, so favor the run read against man alignments. Aggressive run blitzes that crash linebackers immediately open up the bubble throw since the second level defenders vacate the flat in pursuit of the mesh point.