Playbooks

Dig Z Spot out of Shotgun Tight Open runs a five man route concept built around a spot combo to the closed side and a deep dig from the flanker. To the field side you get a corner route stemming vertical then breaking outside, a spot flat route sitting underneath, and a pivot route working back to the sideline as a checkdown for underneath zone defenders. The backside receiver runs a dig that squares across the middle to attack any zone hole vacated by a linebacker dropping to the flat, while the closed side runs a shallow drag/spot combo underneath. This is a zone beater designed to stress Cover 3 by flooding one side with three levels (corner, spot, pivot) while the dig works the opposite hash, and the primary read progression starts with the dig against Cover 3 before working to the flat/spot combo underneath.
Key the middle linebacker drop at the snap, since Cover 3 defenses rely on him to wall off the dig route and any late or lazy drop opens the window for the primary read. Watch the flat defender assigned to the spot/pivot combo, if he sits on the flat route the corner route behind him will be open on a vertical stretch. Man coverage with no safety help over the top gets exposed by the corner route winning outside leverage against a trailing corner or nickel defender. User controlled defenders sitting in a lurk position over the shallow drag will bait you into the dig, so double check leverage before pulling the trigger on the middle read. Cover 2 and Cover 4 shells with two deep safeties can squeeze the dig route into a tighter window, so be ready to check down to the pivot route rather than force the ball into a contested zone.
Use this on early downs or second and medium when you expect zone drops, especially Cover 3 or Cover 4 shells that leave a soft spot behind the linebackers.
Pre-snap, identify if the strong safety rotates down or stays deep, because a two high shell that rotates late usually means Cover 3 and the dig window will open late in the progression.
If the defense shows Cover 2 or Cover 4, hot route the dig into a deeper crossing route or shift your read to the corner route stretching the flat defender vertically.
Pair this play with Bench Z Spot or Zipper X Spot in your call sheet so the defense sees a similar shell and receiver spacing but has to respect a different route breaking to a different level.
Take the shallow spot/flat combo underneath as a checkdown against pressure looks or when your offensive line shows a blitz pickup issue, since the pivot route gives an instant outlet against extra rushers.