Cover 3

Cover 3 is a zone defense with corners and safeties protecting the deep thirds of the field. Each sideline is covered by the corners and the middle of the field by the safety. That leaves four defenders to cover the underneath zones. Cover 3 allows the defense to keep defenders in the box for the run game while continuing to cover deep and prevent the big play.

Cover 3 Philosophy

Cover 3 balances pass coverage with run defense. The extra safety in the box helps protect against the run and the zone coverage underneath can transfer crossers that would cause issues for man coverages. Some teams will also play press Cover 3 outside to prevent easy access throws that would come with off coverage. The Seahawks were famous in the 2010s for their physical style of press bail Cover 3.

While Cover 3 keeps an additional player to help against the run, there are still only four underneath zone defenders and offenses will often try to stress the amount of field that those those players have to cover.

Cover 3 Assignments

Most defenses at the NFL and college levels play match coverage in Cover 3 which institutes man coverage principles when receivers run deep.

Corners:

• No run responsibility
• If #1 runs a route deeper than 10 yards, cover that receiver in man
• If #1 runs shorter than 10 yards or runs across, get eyes to #2 and collect if they enter the deep third

Free Safety:

• No run responsibility
• Pedal and split vertical routes

Nickel / Outside Linebackers:

• Outside gap run contain
• Hands on #2 and funnel inside
• Sink to a depth of 10-12 yards to the top of the numbers and close the window in the curl zone before pursuing routes to the flats
  • The curl / flat defenders must first buzz through the curl zone and take away the throwing window on their way to the flat
    • However, they must not be out-leveraged to the flat in the process

Middle Linebackers:

• Inside gap run support
• Carry seams vertical to 10-12 yards to help the safety
• Wall crossers
• Sink and collect routes in middle hook zone

Cover 3 Variations

Buzz

In Cover 3 Buzz, the defense is disguising Cover 3 as a two-deep safety look. Buzz is very similar to Cover 1 Robber, with the strong safety coming down to the middle hook zone and the linebacker bumping out to the curl / flat. All other assignments stay the same for the defense. Buzz just has one safety dropping from depth to attack the middle hook zone and confuse the offense into making a poor decision.

Examples

On a third and medium against Washington, Seattle has their outside linebacker and nickel in wide alignments to be able to quickly take away any routes in the flats. That leaves them vulnerable to running the ball, but they’re betting on pass given the down and distance. Washington is running Mesh and if Cousins is able to hold onto the ball for a tick longer, he would see the dig coming in behind the shallow drag that he ends up throwing to. Mesh has two crossing routes that end up in the flats, but those crossing routes bait up the hook zone defenders in the middle of the field. With defenders in the flats to attach to those routes, the linebackers don’t need to come down on the drag routes. The corners outside have carried their routes deep and everything else is covered.

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Now, Washington is the one running Cover 3 and the same general high-low concept used against them. The Eagles are running Drive with a shallow from the outside tight end and a dig from the inside tight end. As the hook zone defender comes up on the shallow sit, the dig springs open behind him. Ideally, that linebacker should get enough depth to close that window and the linebacker to the top of the screen is getting more vertical depth to tighten that window as well. He’s running way too flat and without any receiver pulling him that way, he’s left covering green grass.

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Here, we have the Bears running Cover 3 Buzz. Eddie Jackson is playing deep, but on the snap he rotates down into the hook / seam zone. The Nickel linebacker to the top of the screen does a great job of closing the curl window on his way to the flats. He first gets depth under the curl and then continues to widen with the flare from the running back which gives the Cover 3 corner time to break on the curl and be in position if the ball is thrown. Meanwhile, though, Daniel Jones doesn’t identify that it’s buzz and that Jackson has rotated down. Jackson gets there a little early, but he’s there for the pass breakup.

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Cover 3 Beaters

Summary

Cover 3 is one of the most popular coverages at the lower levels and has been adapted and implemented at the college and NFL levels as well. It utilizes three deep players while staying sound in the run game with an extra safety in the box. There are multiple disguises and variations to keep offenses guessing and when played well, is very hard to move the ball against.