Playbooks

Flanker Spot out of Shotgun Split Offset is a classic Spot concept tagged as a Cover 3 beater, and the diagram confirms the layout: the backside receiver runs a corner route up the sideline, the inside slot works a quick hitch to the flat area, and the frontside stacks a corner route on top of a settle route sitting at the sticks with a flat route underneath from the tight end or back. The backside also has a shallow drag crossing the field for a check down against pressure. This is a five man protection with no blocking tags shown, so it is a straight drop back pass designed to attack zone drops with the classic high low spot combo on the frontside. Primary read progression starts with the flat to settle read on the play side, working the spacing between the flat defender and the curl/hook defender, then working back to the shallow drag as the outlet if the zone rotates hard to the numbers.
Pre-snap, check safety depth and spacing since a two high shell with tight safeties often signals Cover 4 or Cover 2, which forces you to work the corner routes on the outside more aggressively. Watch the flat defender post-snap since his leverage decides whether the flat throw or the settle route is the higher percentage window. Beware of a user controlled lurk defender sitting in the shallow drag lane since that is the most common area for a jumped pick six against this concept. Against man coverage with underneath help, the corner routes become the primary reads since the spot combo loses its zone spacing advantage. Watch for a Cover 3 sky or buzz rotation, since a fast rotating safety into the flat can take away the flat throw and force you to hold the ball longer for the corner route to clear.
Use this on third and short to third and medium since the settle route sits right at the sticks and gives you a built in conversion target.
Pre-snap, identify if the defense is showing a three deep shell since this play is specifically schemed to punish Cover 3 drops.
If you see man coverage with no safety help underneath, hot route the settle route into a corner or speed out to create separation instead of running it into a defender's face.
Pair this play with Deep Curls or WR Corners from the same set so you can run a similar route tree that hits the flat and settle areas but stresses different defenders based on how the defense reacts.
Against zone, key the flat defender first since if he sinks with the corner route the flat throw is wide open, and if he jumps the flat the settle route sits down in the vacated window.