Cover 3 (Middle of Field Closed)
Shown above is the basic player distribution into the 7 zones (3 deep, 4 underneath). There are a variety of ways that Cover3 can be played. The differences in how Cover3 is played will have different strengths and weaknesses. Described here are the three primary versions that Cover3 is played.
The terms 'Sky', 'Cloud', and 'Buzz' indicate which player (position) is the designated run force defender on the strong side of the offensive formation. In Cover3, the defender assigned to the Curl/Flat zones are also tasked with being the run force defender - contain all runs and do not allow any run to get outside - set the edge. By changing which position has this responsibility, it also changes which position is covering the Hook zone, which affectspass coverage.
On a passing play, the two Curl/Flat defenders, weakside and strongside, will usually backpeddle to take away the Curl zone, then as the play develops, allow the QB's eyes to take them to the flat. Since throwing to the flat requires a throw towards the sideline, the immediate threats as the ball is snapped are to the Curl zone. So cover the Curl zone first, then the Flat.
Generally speaking, CBs are the best pass defenders, but are the weakest run defenders. LBs are poor pass defenders compared to a defensive back (Safety, CB). These generic characteristics will determine many of the Strengths/Weaknesses listed below.
Cover 3 Sky
Sky represents "Safety", so a safety is assigned to the strongside Curl/Flat zone.
Strengths:
- Strong safety run force
- Strong safety downhill to attack flat
Weaknesses:
- quick pass to #2 WR as safety is still rotating
- possible disadvantage with Sam LB on TE (if TE is a high end receiving threat)
In all these pics, Black are the deep zones, Red is the force defender (strongside curl/flat), Orange are the other three underneath zones.
Safety rotates to strongside curl/flat
Use momentum from the rotation to attack downhill.
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Cover 3 Cloud
Cloud represents "Cornerback", so a Corner is assigned to the strongside Curl/Flat zone. This is a coverage call usually made when there is a deep threat and the defense wants to aggressively jam that WR at the line.
Strengths:
- can aggressively jam #WR like a Cover2 cornerback. Since the Cloud CB does not have deep zone responsibility, he can jam the WR at the line knowing he has deep safety help
- flat zone pass coverage from cloud CB; Corners are typically the best pass defenders
Weaknesses:
- run contain by cloud CB; Corners are typically the weakest run defenders on the defense
- SS assigned to a deep zone
CB is aggressive at the line to disrupt timing of the WR release. SS rotates over to provide help over the top.
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Cover3 Cloud
Video quality is poor, but just check out the CB playing press at the line, then backpeddling into his Curl/Flat zone.
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Cover 3 Buzz
Buzz represents "Backer" (linebacker), so a Linebacker is assigned to the strongside Curl/Flat zone.
Strengths:
- run contain from Sam; the best LB suited for edge contain
- SS in Hook zone for TE/slot WR coverage over middle of field
- safety rotation can confuse the QB (looks like Cover 1 Robber)
Weaknesses:
- strongside flat coverage (Sam) against pass
With the Sam assigned to the strongside curl/flat, and the Will assigned to the weakside curl/flat, this allows a safety to rotate into one of the Hook zones.
Safety attacks downhill on any short routes in the Hook zone.
Notice how the two safeties rotate in Cover 3 Buzz (above).
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Below is
Cover 1 Robber, a man coverage. It's a general rule that Cornerbacks lie, safeties don't lie. Meaning a QB will often key the positions of the safeties to help determine what coverage he is facing. CBs can play off coverage, allowing them to disguise man or zone. It's harder for safeties to disguise since their positioning on the field can give away the coverage.
If there's a safety in the middle of the field (Middle of Field Closed), it's going to be Cover1 or Cover3. If there are two safeties deep, with neither in the middle of the field (Middle of Field Open), it's Cover2 or Cover4.
This is to show how the rotation of the safeties in Cover 1 Robber can look like Cover 3 Buzz.
If the QB is keying the safeties, the SS looks as though he's rotating down to a Hook zone, and the FS to deep middle. Which is exactly what's happening. But the rest of the defenders are in man coverage because it's actually Cover 1 Robber.
A QB that isn't careful and is just keying the safeties can be tricked into seeing something that isn't there.
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Cover 3 "Mable"
The term 'Mable' means 'man coverage'. This type of Cover 3 can be used to combat offensive formations that have Trips to one side of the field and a lone WR on the other (3x1). Mable tells the weakside CB to play man coverage on that single WR, with the rest of the defense playing Cover3 (zone).
Weakside CB locked in man coverage. This call is typically made when that lone WR is to the field side (wide side) and/or has a plus split (far throw for QB). Because that CB vs WR is on an island, might as well lock them up in man coverage.
Cover 3 with the weakside CB in man coverage (back turned to the QB).
