Playbooks

PA FB Sail is a play-action pass out of the Maryland I formation that sells a fullback dive fake before working a classic sail combination to one side. Off the fake, the fullback releases into the flat as the underneath route while a receiver runs a deep corner or over route stacked behind him, and a third receiver on the backside runs a deep dig or crossing route back toward the play, giving the quarterback a full flat-to-deep progression. This is a Cover 2 and Cover 3 beater built to stretch the flat defender and deep half or deep third defender vertically, with the primary read starting at the deep sail route and working down to the fullback in the flat if the corner or deep defender takes it away.
Pre-snap, identify two-high safeties sitting deep, since that usually signals Cover 2 or Cover 4 and tells you the sail route has a clear throwing window before the corner and safety can squeeze it. Watch the flat defender or corner at the snap, if he bites hard on the fullback's play-action fake or sinks too far underneath, the deep sail route behind him is the immediate answer. Key the middle linebacker's reaction to the fullback fake, a linebacker who steps up to fill the run gap opens up easy access to the flat and shortens the field for a quick checkdown. Against man coverage, watch for a slot or nickel defender shadowing the fullback in man, if he beats the fullback to the flat and jumps the route, be ready to work the backside crosser or dig instead. Be alert for a disguised blitz off the edge, since the play-action fake holds the offensive line and fullback release long enough that an unblocked rusher can collapse the pocket before the deep read comes open.
Use this on early downs after establishing HB Blast or FB Dive so the fullback fake in the backfield actually holds linebackers and safeties.
Check the safety alignment pre-snap, if you see two deep safeties sitting at 10 to 12 yards this is a strong Cover 2 beater because the sail route will climb over the flat defender before the safety can rotate over.
Against Cover 3, key the flat corner: if he sinks with the deep route the fullback should be wide open underneath for an easy pitch and catch.
Hot route the backside crosser into a deeper dig if you are getting man coverage looks, since it turns into a solid man beater against Cover 1 or Cover 0 by working away from the play-action flow.
Pair this with PA Boot Slide and PA Boot on early downs to keep the defense guessing on which side the play-action flow is going, then hit PA FB Sail when you diagnose a two-high shell.