Playbooks

Four Verticals out of Shotgun Y Trips Wk sends both outside receivers on the boundary and the trips side vertically up the field while the slot receiver from trips runs a seam route that bends outside near the numbers, creating four vertical stems spaced across the field. The TE from the trips bunch runs a quick out to the flat while the RB stays in to check release and then releases into a route working back across the middle, giving the QB a shallow crossing outlet if the deep routes are covered. This is a zone beater designed to attack Cover 2 and Cover 3 by stretching the safeties and outside corners vertically, with the primary read starting on the safety rotation post snap: read the deep middle first, then work to the seam or the outside vertical based on which safety commits.
Pre-snap, identify the safety depth and spacing since two deep safeties evenly split indicate Cover 2 or Cover 4, both of which are vulnerable to the seam route splitting the numbers. Watch for a single high safety cheating toward the trips side, which signals Cover 3 and means the boundary vertical on the backside will have single coverage with no safety help. Post-snap, key the flat defender's drop, since if he sinks too deep to cover the seam the TE's out route to the flat becomes an easy completion underneath. Look for user-controlled safeties sitting in a deep lurk over the middle, which shuts down the seam read and forces the QB to work the outside verticals or check down to the RB's crossing route. Beware of Cover 2 Man or man blitz packages that disguise as zone, since a jumped seam route or a blitzer coming off the edge can blow up the play before the deep routes develop, so check protection and hot route the RB to block if you see extra rushers.
Use pre-snap motion or a quick peek at the safety alignment to confirm two-high versus one-high before the snap, since this play is built to punish two-high shells.
If the defense shows Cover 2, target the seam route running up the numbers before the safety can rotate over, since that window closes fast against a good user in the deep middle.
Against Cover 3, work the flat route or the crossing route from the RB as a checkdown if the deep routes are blanketed, since the single deep safety can only take away one vertical threat.
Hot route the TE's flat route into a deeper option route if you are facing a Cover 4 shell, since the flat conflicts with the underneath defenders more than the deep coverage.
Pair this play with Fl Dig or Fl Short Dig from the same set to keep defenses guessing between vertical shots and intermediate breaking routes, forcing linebackers to respect both the seam and the dig at the same depth.