Playbooks

Middle Hi Lo aligns out of Shotgun Empty Base Flex with five receivers and no backfield help, so every route is a pure pass concept with zero play-action mesh point despite the tag. The diagram shows a dagger concept on the right side with the outer receiver running a vertical go to clear the deep coverage while the inner slot runs a deep dig underneath it, plus a post from the right slot bending across the middle for a true hi lo read on any single-high defender. On the left, the two receivers work a curl and flat combo for an underneath answer against zone drops. The primary read progression starts with the post working from deep to intermediate, then works to the dig sitting down in the void, and finally checks down to the curl flat side if the middle is capped.
Watch the deep safety alignment before the snap, since a single high safety cannot cover both the post and the dig at the same depth. Post snap, key the middle linebacker's drop, because if he sinks with the dig route it opens a throwing lane behind him for the post. Cover 3 and Cover 1 are the most vulnerable shells here since the hi lo stresses the middle third defender with two crossing routes at different depths. Two high safety shells like Cover 2 or Cover 4 can shut this down if the safeties stay deep and squeeze the post, forcing the quarterback to settle for the curl flat combo underneath. Watch for a user controlled lurk defender sitting in the throwing window of the dig route, since aggressive human defenders will jump this route if the quarterback stares it down too long.
Use this out of empty formations on third and medium to long when you need to attack the middle of the field with numbers.
Pre-snap, identify if the defense is showing single high or two high safeties, since the post over dig hi lo is deadliest against single high shells like Cover 3 or Cover 1.
If the corner presses the outside go route, hot route it to a slant to turn this into a quick man beater against man coverage.
Pair this play with Verticals or Four Verts in the same set to keep defenses honest on deep shells, then come back to Middle Hi Lo once the safety starts cheating toward the boundary.
Snap the ball quickly once you see the dig route window open, since holding the ball too long lets underneath zone defenders drift into the throwing lane.