Playbooks

Curl Pivot Dig out of Shotgun Empty Quads spreads five eligible receivers across the formation with no backfield help, so this is a pure passing concept with zero run support built in. The outside receiver at the bottom runs a quick out breaking route, the inside slot receiver pivots and works back to the middle on a dig that crosses the field, the next receiver runs a curl and settles down in the void, and the backside X sits on a vertical stem before breaking. This is a zone beater at its core, using the curl and dig combo to sit in the soft spots of zone coverage, with the primary read progression starting at the dig, then working out to the curl, and finally to the boundary out route if the middle is clogged.
Pre-snap, identify whether the defense is showing zone drop shells like Cover 3 or Cover 4, since this concept is built to exploit the seams and hooks that those coverages leave open underneath. Watch the flat defender and the hook to curl linebacker post-snap, because if either one sits too deep or bites on the curl, the dig behind them will be wide open for the quarterback's first read. Man coverage with no help over the top on the pivot route can be had if the defender jumps the pivot fake, so key whether the corner or nickel is playing outside leverage before the ball is snapped. This play struggles against a well disguised Cover 2 with a hard flat squeeze and an active middle linebacker, since that combination clogs both the dig lane and the curl window simultaneously. On the defensive side, sending a lurk defender to rob the dig or spying the intermediate middle with a linebacker will shut down the primary read and force the quarterback into a longer developing checkdown.
Pre-snap, check for two-high shells since the dig has to sit down in the honey hole between the underneath zone and the deep safeties, and this play thrives when linebackers drop shallow and leave that window open.
Use motion or a hot route on the backside vertical route to convert it into a man beater if you see press man or a single high safety rotating late.
This play works best on second and medium or third and medium since the dig needs time to develop and the sticks are realistically in range for the intermediate crosser.
Pair this play with Four Verticals from the same Empty Quads set to keep defenses honest, since if they start sitting on the shorter curl and out routes you can hit them over the top with verts using the same formation look.
Combine with WR Screen out of this set as a changeup to punish linebackers who key hard on the quads side and crash downhill after seeing the dig conversion week after week.