Playbooks

Mills out of Pistol Strong Slot Close is a classic Cover 4 beater built around a post/dig combo on the backside and a deep vertical shot on the strongside. The backside X runs a corner route off the outside stem while the slot receiver runs a dig underneath into the vacated middle, creating the Mills concept clash on any deep half or quarter safety. On the strongside, the TE/flex runs an out to the sideline while the outside WR climbs the seam vertically to stretch the defense before curving up the numbers, and the backfield runs a check release swing route underneath. This is a true dropback pass with no play-action or RPO tag, so the primary read starts with the dig-to-post combo on the backside before working to the strongside seam and flat.
Pre-snap, check for two deep safeties split evenly since that quarters shell is exactly what the corner/dig combo is designed to attack. Watch the strongside safety and outside linebacker depth at the snap, if they widen with the seam route the dig behind them will be wide open. If the defense shows single-high Cover 3 or Cover 1, the corner route can get taken away by the deep third defender, so be ready to check down to the flat or swing route. User-controlled defenders sitting in the middle of the field as a lurk defender can jump the dig route, so look off the safety before committing to the crossing route. Man coverage with no help over the top is a green light to throw the corner route early since the receiver's outside release creates natural separation against man defenders.
Pre-snap, identify whether the defense is showing two-high or single-high safeties because Mills is designed to punish quarters and Cover 4 shells where the safety has to choose between the corner and the dig.
If the corner route draws a deep half safety, put your eyes on the dig immediately since the linebacker flowing to the seam opens up the crossing route in behind him.
Use the strongside out route as a quick alert versus Cover 2 or Cover 3 if the flat defender sinks too deep, since it is an easy completion for positive yardage on early downs.
Pair this play with PA Deep In in your call sheet since both attack similar coverage shells but from different pre-snap looks, keeping the defense guessing between the post/dig combo and the deep in.
Best used on second and long or third and medium when you need a shot play but still have a checkdown valve through the backfield swing route if the coverage jumps the deep routes.