Cover 4 (Quarters) Defense

How Cover 4 Works

Each corner and safety takes a deep quarter, and three underneath defenders (in Crucible's diagram the Sam and Will in the flats and the Mike in the hook) cover the short zones. The safeties play shallow enough to fit the run and read the No. 2 receiver. When No. 2 goes vertical, the safety takes it. When No. 2 breaks short or outside, the safety helps on No. 1.

With four defenders deep, quarters is one of the best answers to vertical passing concepts.

Where Cover 4 Is Weak

• The flats. With only three underneath, quick flat throws often have room.
• Underneath crossers: shallow and drag routes under the linebackers, away from the deep defenders.
• Safety conflict. A receiver who looks vertical and breaks off, or a combination that reads differently than it starts, can catch a safety on the wrong receiver.
• Outside hitches and curls against corners playing deep.

How to Recognize It

• Two high safeties sitting shallower than Cover 2 Tampa safeties, close enough to fit the run.
• Corners off the ball, playing deep over the outside receivers instead of squatting.
• Motion gets a bump. Nobody runs across with the receiver.
• At the snap the safeties sit or shuffle instead of bailing, read No. 2 and come downhill fast on run action, while the corners backpedal and stay deep.
• Two-high safeties who sit at the snap is quarters. Two-high safeties who backpedal and widen, with corners squatting in the flats, is Cover 2 Tampa. Coaches call this reading the safeties' departure angle.

How a QB Reads It

Take what is underneath: the flats, outside hitches against deep corners and crossers under the linebackers. For a bigger play, make a safety wrong with a No. 2 receiver who looks vertical and breaks off. Do not force verticals into four deep defenders.