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Jets System Primer: Fitting the Pieces Together on Defense

NFL: New England Patriots at New York Jets Vincent Carchietta-USA TODAY Sports

Hall of Fame coach Tom Landry held a masters degree in industrial engineering. He applied the engineering principles he learned in school when he built his defenses. His units needed to be structurally sound with each part supporting one another. Landry was known to give a negative grade in film review to players who made a play that wasn’t their assignment within the defensive playcall. Even if it was a tackle for a loss, Landry reasoned somebody else was assigned the role to make the play. The tackler had abandoned his assignment and thus left the defense vulnerable.

I didn’t want to jump too deep into the Jets’ new schemes until I at least saw them on the field. We know what Robert Saleh did in San Francisco. We know his influences in his early days as a coach. We had a pretty good idea what some of the principles would be, but I wanted to see the defense in action to know for sure what we would be looking at.

We are still only two games into his tenure as Jets head coach so I am sure some things will be adjusted as we move forward, but I am beginning to get a sense of what the Jets want this defense to be and why the roster was constructed as is.

Today’s NFL defenses are very complex, and play calls vary based on opponent and game situation.

However, in neutral situations I get the sense this is the base defense for the Jets.

It’s a very basic Cover 3. Responsibility for the deep part of the field is divided into thirds. One safety has the middle third. The outside thirds are the assignments of the two outside corners.

Underneath there are four zone divided by whichever safeties, slot corners, and linebackers align there.

As you may know, Saleh coached early in his NFL career with the Seattle Seahawks under Pete Carroll. The Seahawks were known for having an iconic defense from this era built around a secondary nicknamed the Legion of Boom.

The Seahawks ran their share of Cover 3, but they had a very talented cornerback group led by Richard Sherman.

One of the weak spots in a typical Cover 3 defense is in the underneath portion of the field near the sideline. Since there are only four players assigned in underneath zones, they are stretched horizontally across the field to their breaking point. There is a tremendous amount of ground to cover, really too much for four players to handle.

Carroll frequently gave his outside corners the responsibility of covering the short outside area before they dropped into their deep zone.

That’s a luxury that comes from talent. The Jets lack that type of cornerback play so they probably will have to ask less. Instead of giving their corners the assignment of covering the short part of the field at the snap, outside corners at least for now will likely be asked to play just the deep part of the field and protect against the big play.

If you think about it, this approach probably goes a long way toward explaining why the Jets handled the cornerback position the way they did this offseason. You need talented corners if you are going to give them assignments more complex. You also need talented corners if you want to play the way Rex Ryan did and have Darrelle Revis and Antonio Cromartie types run step for step with the other team’s best pass catchers all game long.

The job of handling deep zones without contesting the short area is much easier and simpler. There are many more corners capable of handling that assignment than are capable of handling the Sherman/Revis/Cromartie assignment.

You don’t need to break the bank to find corners to do this job so the Jets went young and cheap with developmental players full of enthusiasm. The staff presumably hopes to coach these guys up, and if they develop maybe one day they will be capable of handling more.

Still you do have that vulnerability in the short passing game to the sideline. To make this defense work, your outside corners need to be able to rally to the football and willing to tackle on completions in front of them.

Every defensive play has its weaknesses. How much can they be negated?

Even if Brandin Echols isn’t going to be in position contest a short pass if he can minimize the damage on these plays, it helps the unit succeed.

This stuff requires a team effort, though. You also need players in the middle of the field fast enough to get outside and willing enough to make tackles like slot corner Michael Carter II here.

Linebackers like CJ Mosley will also need to cover a lot of ground and tackle in this vulnerable area where short passes go.

I can’t help but think back to training camp where Mosley came in slimmed down so that he could play faster. The Jets also picked a pair of safeties in the NFL Draft who they converted to linebacker.

Doing things like this builds a speedier linebacker group capable of covering more ground, which clearly is needed given the circumstances. It does create a challenge, however. A slimmed down Mosley and safeties at linebacker might make the position faster, but they are also smaller. Playing close to the line of scrimmage, they will likely struggle to shed blocks in the run game.

How do you deal with that? There are a couple of ways.

Am Cover 3 play only requires one deep safety. The deep part of the field is covered by that safety and two corners, which means the second safety can move close to the line of scrimmage to help with the run on most plays.

Still a safety is another skinny body also unlikely to be able to shed a block.

Perhaps to combat the lack of bulk at linebacker, the Jets have frequently gone big on the defensive line with John Franklin-Myers at defensive end.

At close to 290 pounds, Franklin-Myers is bigger than your typical defensive end on a four man line. He profiles as more of a typical interior player with this type of look. The types of defenses where he typically would line up as a defensive line would be three man lines where all of the linemen have a little extra bulk.

I would guess the Jets are using Franklin-Myers this way to help protect these linebackers. Since there is extra size up front, the Jets are more capable of holding the point of attack and preventing blockers from getting out to the linebackers.

Ten years ago SB Nation’s Field Gulls described defensive line assignments in Pete Carroll’s system at a point where the Seahawks also had a strikingly large group of defensive linemen.

Right now, the Seahawks run a primarily one-gap-and-hold 4-3. Usually, when you hear “one-gap” 4-3, you should think of Kiffin/Tampa 2 or Phillips 3-4 style, attacking relentlessly through single gaps to overwhelm the opposing offensive line. But that’s not the case for us. One-gap-and-hold sees linemen take on single gaps (and often two gaps), but not to penetrate, rather to outmuscle the offensive line and choke out any running attempts.

I haven’t heard Saleh talk about gap responsibilities in his system, but it would stand to reason this was an objective. The defensive linemen in this scheme have to muscle the offensive linemen. If the offensive linemen can get to the linebackers and block them, it is going to be a long day at the office.

If they don’t you’ll have linebackers making plays.

This might be worth keeping in mind if you find yourself ready to bash a Jets interior defensive lineman for not putting up stats. He might only be free to make plays after he first secures his gap and eats up blockers.

All of this also helps to explain why the Jets invested so much money in Carl Lawson and why his loss will be felt so deeply this season.

The Jets have a number of quality interior pass rushers. Franklin-Myers himself has an ability to get to the quarterback, but again pass rushing might not be the first responsibility.

In any event, interior pass rushers don’t generate as much pressure as edge guys. JFM might be adept at pushing the pocket, but doesn’t have the speed to get around the edge and to the quarterback. Only one player on the field will for the Jets compared with the two many defenses have at either end of the line.

Just as the difficulty of these assignments explain why the Jets felt they could invest so little at corner, this edge role explains why the team felt it needed to spend so much on Lawson (and then trade for a second Lawson).

As always, any scheme has its strengths and weaknesses. I am not here to tell you this approach is superior to others. I am just trying to relay what it seems like the objectives are for the Jets on defense. As with any system, this will be as effective as the players who take the field and their execution.