Cover 3

Three deep thirds, four underneath.

Three deep defenders split the field into thirds, four underneath in zone. The NFL's base zone — vulnerable in the seams and the flats.

How each scheme beats it

Four verticals stresses all three deep defenders — the seams are the throws. Flood one third with three routes; curl-flat vs. the underneath zones.

Curl-flat and drive concepts live here — sit in the soft spots. Run vs. the light box; play-action holds the underneath defenders.

Play-action seam shots between the thirds. Inside runs vs. four-underneath spacing — the deep thirds can't help against the run.

Bootleg — flood the flat and throw the deep over behind the hook defenders. Outside zone vs. corners playing deep thirds.

Play-action seams off the zone read; the QB run game attacks the edges the deep thirds vacate. RPO slants into the soft underneath zones.

Seams and deep posts between the thirds — that's the whole passing game vs. Cover 3. Bend posts away from the middle-third safety.