Playbooks

Mtn Z Under runs a mountain point route concept with a Motion tag out of Pistol Weak Slot Open. Off the snap, the two outside receivers push vertical seams to stretch the deep safeties while the slot receiver runs a deep drag under across the middle from the strong side. The Z receiver on the boundary side works an under route into the flat and up the sideline, and the running back releases underneath into a check down flat route on the weak side. This is a zone beater play-action style passing concept built to attack seam voids and hi-lo the underneath zone defenders, with the primary read progression starting at the deep drag crossing the field, then working to the Z under route in the flat, and finishing with the check down to the back if the middle of the field stays clogged.
Identify user controlled linebackers before the snap, if they are sitting deep in the middle zone they can jump the deep drag route and force you to your check down early. Watch cornerback depth on the outside receivers running the vertical seams, soft coverage at the snap signals zone and tells you the seams will be there longer. Cover 3 with a hard middle zone linebacker shuts down the deep drag read, so key on whether the middle of the field is occupied before committing to that route. Man coverage with no safety help over the top opens up the vertical seam routes immediately, take the shot up the field before the pocket collapses. Watch for blitz packages that bring extra rushers off the edge, since the running back is your check down option, a fast blitz eats up the time needed for the deep drag to develop and forces a quick decision.
Use the pre-snap motion to identify man versus zone before the snap, if the defender follows across the formation you know you are getting man coverage and can lean on the deep drag to work away from the trailing defender.
Look at the safety alignment before the snap, two high safeties tell you the seams are more open for the vertical routes, while a single high safety means the deep drag over the middle becomes your primary target versus the middle void.
This concept is best called on second or third and medium since it takes a beat to develop with the deep drag crossing the full width of the field, avoid calling it in obvious hot route blitz downs.
Hot route the running back to a stick or angle route if you are facing heavy underneath zone traffic, this gives you a faster answer than the check down flat route drawn up.
Pair this play with Mtn Y Stick and Mtn Flood earlier in a series, all three share the same mountain shell look which lets you disguise which route concept is coming and keep linebackers guessing on their zone drops.