In today’s installment of the “NFL 101” series, former NFL defensive back Matt Bowen breaks down the basics of Cover 1 to give you a better understanding of the game.

Click here for a breakdown of the core NFL route combinations.

Cover 1 is a first-day install scheme with defenders playing man coverage from an outside leverage position and using the free safety help in the middle of the field.

The core idea is to take away outside breaking routes by alignment (outside shade) and force (or “funnel”) receivers inside of the numbers to the free safety and underneath the “hole” defender.

A defense that is dependent on solid technique in the secondary, Cover 1 allows teams to create eight-man fronts (strong safety drops into the box) with the protection of the free safety over the top.

Today, let’s use the All-22 coaches tape to break down the basic alignments, leverage and responsibilities in Cover 1. We'll also examine how teams will use a “Robber” look and a “jump” call to counter man-coverage beaters.

Key Cover 1 Terminology

Before we get into some All-22 examples to break down Cover 1 alignments, I want to discuss some key terminology used in man coverage.

Leverage: Defenders in Cover 1 align with an outside shade. This means defenders align on the outside shoulder (or outside eye) of the receiver and maintain that leverage throughout the route scheme, either by weaving in a backpedal or opening the hips from a press-man position.

Cushion: This is the initial distance between the defender and the receiver. In off-man, a cornerback will align at a depth of seven to eight yards and only get out of his backpedal once the receiver has broken the cushion—forcing the defender to open and run.

Flat-Foot Read: This is used in off-man. Defenders will not get into their backpedal until the receiver has cleared the three-step concepts (slant, hitch, etc.). This allows defenders to stay square, read through the quarterback and drive on the three-step game. Once there is no threat of a three-step route, defenders will get their eyes back to the receiver and gain depth in their pedal.

Base Alignments and Responsibilities in Cover 1

Let’s take a look at how the defense aligns in a Cover 1 using an example from the Bears-Rams matchup.

With their base 4-3 personnel on the field, the Bears counter the Rams' Tank/22 personnel (one wide receiver, two tight ends, two running backs) with an “Over Cover 1” call.

Both cornerbacks play the No.1 receivers from an outside leverage position: Z receiver on the closed (strong) side with the U tight end to the open (weak) side (the second tight end becomes the X receiver in Tank/22 personnel).

The strong safety plays No. 2 (Y/tight end) to the closed side. He drops down into the front and aligns from an outside leverage position to drive to the hip of the tight end in order to use his help on any inside breaking route.

Underneath, the linebackers ("Sam" and "Will") match the first running back strong/weak. If the running backs block, the linebackers can use a “green dog” technique (rush to coverage) or zone up underneath to read the quarterback.

That leaves the "Mike" linebacker to drop as the underneath hole defender. This is done to help inside on the short-to-intermediate passing game versus concepts such as the slant or Hi-Lo (inside crossing routes).

This gives the defense two levels of “help” in Cover 1 (free safety over the top, Mike ‘backer underneath). And because of the initial alignment (outside shade), every defender (versus standard receiver splits) is taught to use their help inside.

Inside Shade vs. Plus Splits

Why would a cornerback align with an inside shade in Cover 1?

Anytime a receiver is in a “plus” split (two to three yards on top of the numbers), defenders can take away the inside breaking routes by alignment while using the sideline as their help.

Remember, from a “plus” split, there are only two routes a receiver can run with an outside release: a fade or comeback. That’s it because of the restrictions the boundary puts on the out route, 7 (corner), etc.

Here’s an example of the inside shade from the Cardinals’ Patrick Peterson versus the Eagles’ DeSean Jackson.

With Jackson in a “plus” split (three yards on the top of the numbers, ball on the far hash), Peterson aligns on the inside shoulder of the wide receiver.

This allows Peterson to take away the slant/smash by alignment while also having the ability to use the sideline as his help versus the fade/comeback.

And when Jackson releases outside, Peterson is now in a position to “pin” (or squeeze) the receiver to the boundary to stack on top of the fade or limit the comeback.

Cover 1 vs. Slot

In Cover 1, defenders have to “travel” with their coverage. Whether that is by alignment or motion, you will see safeties, cornerbacks and linebackers adjust based on the formation/pre-snap movement.

This is why NFL offenses window dress their pre-snap looks, as it forces the defense to show man or zone, depending on which defenders move to match their coverage.

Here’s a look at the Seahawks' Cover 1 versus the 49ers out of a Pro Slot I formation with Regular/21 personnel (2WR-1TE-2RB) on the field.

Cornerback Byron Maxwell “travels” to the open side of the formation (slot side) to match Anquan Boldin (Z) while strong safety Kam Chancellor drops down to the closed side of the formation to play tight end Vernon Davis (Y).

Up top, cornerback Richard Sherman aligns with an inside shade (versus a “plus” split) and free safety Earl Thomas drops to the deep middle of the field.

Underneath, the Seahawks play the "I" formation the same way the Bears did in our first example (first strong, first weak) with the Mike ‘backer dropping to the underneath hole.

Now, let’s check out the leverage of the defenders after the snap.

Both Maxwell and Chancellor maintain their outside leverage position (from a press technique) and are now in a position to funnel those receivers to the Mike ‘backer or Thomas in the deep middle of the field.

Sherman (because of the “plus” split) drives to the hip of Michael Crabtree on the outside vertical release to use the sideline as his help.

Nickel Cover 1

There are multiple defensive sub-packages across the NFL out of nickel, dime, ruby (3DL-2LB-6DB), etc. that use Cover 1 as a core coverage.

Let’s look at Cover 1 out of a base nickel package from the Dolphins-Patriots matchup.

With the Dolphins aligning in a 3x1 “Doubles Slot” formation out of Posse/11 personnel (3WR-1TE-1RB), the Patriots counter by bringing an extra defensive back on the field to play Cover 1.

The nickel defender aligns to the closed (strong) side of the formation and plays the H (or slot receiver) with the cornerbacks matching to the Z/X in press looks.

To account for the Y (tight end) and R (running back), the Patriots drop the strong safety from a two-high disguise while matching the linebacker to the back.

This leaves the second linebacker in the game as the underneath hole defender with free safety Devin McCourty dropping to the deep middle of the field.

Even with nickel on the field, the same rules apply for the defense in its Cover 1 alignments and responsibilities versus three wide receivers.

Off-Man Alignment

To give you a better idea of the depth and alignment of a cornerback in off-man, let’s look at this example from the Panthers-49ers matchup.

Check out the depth of the 49ers cornerback. He is off (and to the outside) between seven and eight yards. This allows the cornerback to play through the three-step game (flat-foot read) and get into his pedal to maintain the cushion versus the wide receiver.

Once the wide receiver eats up his cushion, the cornerback will have to open his hips/run, but this is the alignment you want to see from your defensive backs in off-man.

Cover 1 “Robber”

In “Robber” coverage, think of Cover 1 assignments with the strong safety dropping down into the hole. This allows defenses to disguise their looks (usually done from a Cover 2 shell) and eliminate inside crossing concepts.

Here's an example of Cover 1 “Robber” from the Seahawks’ Super Bowl win over Peyton Manning and the Denver Broncos.

The Seahawks have their nickel package on the field versus the Broncos' Posse/11 personnel in a 2x2 “Doubles” formation with a “Vice” alignment (double stack).

With the defenders playing from an outside leverage position, the linebacker bumps out to cover the tight end and Chancellor drops into the hole (“robber”).

Because of the Hi-Lo crossing concept, Maxwell has to bubble over the inside traffic and is stuck in a trail position versus Demaryius Thomas. However, look at Chancellor. As the hole defender, the Seahawks strong safety reads through to the quarterback, identifies the underneath crossing route and is in the proper position to drive on the throw.

The end result is a minimal gain for the Broncos with Chancellor delivering a clean, violent shot on Thomas as the underneath “robber” in Cover 1.

Cover 1 “Jump” Call

The “jump” call is another way to limit NFL offenses that use Hi-Lo crossing routes by adjusting to a reduced split (tight to the core of the formation) or by “cutting” the pre-snap motion.

Let’s go to the Chiefs-Eagles matchup to highlight the “jump” call versus a Hi-Lo concept.

With the Eagles sending DeSean Jackson on short, "divide motion" (motion to the core of the formation), the Chiefs use the “jump” technique to avoid the cornerback chasing the shallow drive route from an outside leverage position.

In the “jump” call, the free safety will “cut” the receiver, with the cornerback replacing him in the deep middle of the field. The safety has to take an angle to the inside shoulder of the receiver (he has to avoid over-running the route) with the cornerback now becoming the deep inside help in Cover 1.

This plays out perfectly for the Chiefs with the free safety taking away Jackson on the shallow drive route (he avoids the inside traffic with the “jump” call) and the cornerback replacing in the deep middle to protect against a possible post route.

The Importance of the Free Safety in Cover 1

What we looked at today is just the start when discussing Cover 1 in the NFL. Think of it as an introduction to man coverage from an alignment and technique perspective.

In the future, I will break down how to defend versus stack/bunch alignments, plus run through the multiple man-pressure schemes that show up every Sunday in the pros.

However, in any form of Cover 1, the free safety is the key.

You need a player in the middle of the field who has range and ball skills, plus the ability to identify concepts and create clean angles to take away the seam/post.

That’s why the Seahawks can consistently limit offenses playing single-high safety defenses (Cover 1, Cover 3) with Earl Thomas in the deep middle of the field, and it’s the same reason the Saints paid Jairus Byrd $28 million guaranteed this offseason.

Having talent at the free safety position allows the corners and underneath defenders to play aggressively in their techniques with protection over the top.

And when you combine the ability of the deep middle of the field defender with solid technique/fundamentals underneath, there is nothing better than challenging receivers and locking down an offense in Cover 1.

Seven-year NFL veteran Matt Bowen is an NFL National Lead Writer for Bleacher Report.

Follow @MattBowen41