How Smash works

High-low corner-flat combo.
Outside receiver runs a hitch / short curl (4-6 yds) underneath; inside receiver (slot in 5v5/6v6/7v7, TE/Y in tackle) runs a corner (12-15 yds) over the top.
Beats Cover 2 — the corner takes the flat receiver, the safety can't cover the corner.

Coach the details

Every player's job

Call sheet

Defensive lookCover-2 killer — the corner over the top puts the safety in a no-win choice and the hitch underneath is the safe check-down.
Early downsReliable on 1st-and-10 or 2nd-and-medium against a 2-shell team.
Defensive lookCoach corner-first vs zone — the hitch is the free five yards only when the corner sinks.
Defensive lookVs two-deep, work the corner into the honey hole behind the squatting corner and in front of the safety; vs single-high it's a straight one-on-one for the corner.

Pre-snap to post-snap

Cover 0 — Deep balls — there is no safety help, so a step on a man is a touchdown
Cover 1 — Crossers and mesh — natural rubs spring a man defender
Cover 2 — The deep sideline 'honey hole' behind the corner and in front of the safety (corner route)
Tampa 2 — The two deep 'honey holes' outside the hashes — behind the corner, in front of the safety (corner route)
Cover 3 — The flats — four underneath defenders can't cover all five underneath zones (curl-flat / slant-flat)

Cover-2 killer — the corner over the top puts the safety in a no-win choice and the hitch underneath is the safe check-down.
Reliable on 1st-and-10 or 2nd-and-medium against a 2-shell team.
Coach corner-first vs zone — the hitch is the free five yards only when the corner sinks.

Troubleshooting

Hold it vs quarters (Cover 4), where a deep-quarter safety caps the corner and it gets bracketed — go underneath instead.
The 12-15-yard corner needs a beat to develop, so it's not your answer against unblocked pressure.
Corner depth too shallow — the safety squeezes it. Aim for 12-15 yards before the break.
Hitch settles at the wrong depth; should be at 5 yards with eyes back to the QB by the third step.
QB throws the hitch first against zone — wrong read. Check the corner first, dump the hitch if covered.
Receivers cross the same vertical lane and create traffic. Outside should win to the sideline; corner climbs to the boundary.