Playbooks

Mtn Double Post is a motion-based pass concept out of Shotgun Spread Y-Flex Wk that sends the pre-snap motion man on a swing/flat route to the boundary while the backside stacks two vertical post routes from the outside receiver and slot. The lone receiver to the closed side runs a flat breaking out route, giving you a three-level stretch with the flat as the checkdown and the two posts working the deep middle. This is a man and Cover 2 or Cover 4 beater with no blocking concerns since it is a straight drop back pass, and the primary read progression starts with the inside post against the safety, works to the outside post if the safety bites on the shallow route, and comes down to the flat route as the checkdown against a blitz or if both posts are covered.
Read the safety alignment before the snap, two high safeties invite the double post concept while a single high safety means you need to bracket the middle of the field with a robber or spy. Post snap, watch for a user controlled safety flowing to the deep middle, that lurk threat can undercut both posts if he reads the quarterback's eyes early. Key the linebacker depth on the flat route side, a linebacker sitting in a shallow zone can jump the checkdown and create a turnover if the quarterback stares it down. This play struggles against Cover 3 with a rangy deep middle defender who can shade to either post, so disguise coverage by delaying safety rotation until after the snap. Man coverage with no help over the top is the easiest shell for this play, so if you see man alignment on both posts with no safety help in the middle, expect an explosive completion.
Use the pre-snap motion to identify man versus zone by watching if a defender follows the motion man across the formation.
Against Cover 2, target the outside post since the double post concept is designed to split the safeties before the deep half defenders can convert and gain depth.
Against Cover 4 or Cover 3, hit the inside post quickly before the safety rotates over the top, since one deep defender has to cover two vertical threats in the same area.
Save this play for second or third down and medium to long distance when you need to attack the middle of the field with dependable post shots.
Pair this with Four Verticals or PA Dagger from the same set to keep defenses honest, then come back to Mtn Double Post once you see safeties cheating toward outside verticals.