Playbooks

Corner Strike is a play-action style route concept out of Pistol Bunch with 11 personnel, though the diagram shows a straight dropback pass design. From the bunch alignment, the inside receiver runs a sharp corner route breaking outside toward the sideline (the red route), while the two other bunch receivers work a deep crosser to the far sideline and an underneath drag away from the corner route. On the backside, the single receiver runs a deep in-breaking route across the middle, and the running back releases into a short flat or check release near the line. The primary read progression starts with the corner route out of the bunch attacking the void behind underneath defenders and in front of deep coverage, then works to the backside deep in-breaker if the corner is capped, with the drag and flat routes serving as checkdown options against pressure.
Watch the flat or curl defender at the snap: if he sinks with the drag route, the corner route to the outside will be open in the void behind him. Check the deep safety alignment before the snap: a two high shell with safeties shaded outside leaves the backside deep in route open against Cover 2 or Cover 4. If the cornerback aligned over the bunch shows off coverage, expect a soft corner that squats on the corner route, making the deep in or drag the better answer. Post-snap, identify any user lurking underneath in the middle of the field, since that defender can undercut both the drag route and the deep in if he reads the quarterback's eyes early. Cover 3 sky or buzz coverage with a fast-flowing flat defender is the toughest matchup for this concept, since it can squeeze the window on the corner route and force a checkdown to the flat.
Attack Cover 3 and Cover 4 shells where the flat defender has to choose between the underneath drag and the breaking corner route.
Use pre-snap motion or a hot route on the single receiver's deep in to convert it into a quicker breaking route if you see press man across from him.
This play pairs well with Flanker Drive and Curl Flat from the same set, since both look similar pre-snap but attack shallow and intermediate zones, keeping defenders honest against the deeper corner shot.
Best used on second or third and medium to long, since the corner route and deep in both need time to develop against zone drops.
If the defense shows Cover 2, look immediately to the corner route since it settles in the deep half seam before the safety can rotate over.