The New England Patriots' defense is registering subtle yet key improvements lately. One of the main reasons has been the success of their blitz.
Head coach Bill Belichick and defensive coordinator Matt Patricia have turned their personnel loose in recent weeks.
An injury to top pass-rusher Chandler Jones has contributed to this schematic switch. However, the Patriots have also been playing more to the strengths of their defenders and 4-3 system.
The Patriots are leaning on the blitz to shut down offenses. Some examples from Week 13's win over the Miami Dolphins show how they are doing it.
Note: All screen shots credited to CBS Sports.
Blitzing the run
They are still suspect against the pass, but there is little wrong with New England's run defense. The Patriots are ninth against the rush, allowing 100.8 yards per game.
Blitzing the run with linebackers and safeties is a major reason why. Reggie Bush and the Miami Dolphins recently found out how aggressively New England attacks the run.
In the first screen shot, the Patriots present the Dolphins with a five-man line.
Linebacker Dont'a Hightower usually matches up with the tight end and does so here. On the other side, defensive end Rob Ninkovich is highlighted.
As a former linebacker, Ninkovich often adopts a two-point stance. This gives the Patriots' hybrid 4-3 front the appearance of a 3-4.
Behind this heavy front, New England has a pair of big inside linebackers—Brandon Spikes and Jerod Mayo. They are the main weapons against the run, and their potential attack lines are indicated by the red arrows.
On this particular play, it's Mayo who blitzes. His attack is shown in the screen shot below.
Mayo quickly attacks downhill, indicated by the red arrow. He times his blitz extremely well.
The highlighted portion shows defensive tackle Brandon Deaderick drawing a double team. Because of their tremendous size at defensive tackle, the Patriots usually draw double teams in the running game.
This creates excellent blitz lanes for Mayo and Spikes, and the Patriots are taking full advantage.
The screenshot below shows what Mayo's blitz does to this running play.
With Mayo already in the backfield and beating the fullback, Bush immediately has to alter his path. The highlighted portions show the natural wall the Patriots have built along the line of scrimmage.
In particular, Hightower and Ninkovich have both set a hard edge, denying Bush any cutback lanes. It is Ninkovich who eventually made the tackle for a loss.
Later in the game, the Patriots again blitzed the Miami running game. The screenshot below shows how.
This time it is safety Steve Gregory who is used to spearhead the attack. Gregory is highlighted, getting ready to blitz the open side of the formation.
Again the Patriots have used Hightower to match up with the tight end and create a five-man line. By bringing Gregory from the other side, the Patriots can again set the edges and box the runner inside.
Blitzing off the edge forces running plays into the middle—and the strength of New England's defense.
The screenshot below shows how Gregory destroys this run.
He comes free from the edge and Ninkovich also gets into the backfield. Again the Patriots have created that same wall in the middle. Gregory is untouched and helps bring Bush down for another loss.
Green dogs in the red zone
To take better advantage of the attacking instincts of players like Mayo, the Patriots have started using more "green dogs." This term simply refers to a blitz executed only if a defender's primary coverage assignment stays in to block.
Here's a look at a superbly executed green dog by Mayo, with the Dolphins threatening to score.
The Patriots are fielding dime personnel and showing a basic, man-under coverage look. In this coverage, Mayo's responsibility is the lone running back. Both players are shown in the highlighted portions.
At the snap, the running back's actions allow Mayo the freedom to blitz, shown in the screenshot below.
The highlighted portion shows the running back has turned in to help block Trevor Scott. This gives Mayo the green light to attack.
He quickly makes up his mind and blitzes quarterback Ryan Tannehill. His blitz path is indicated by the red arrow.
The Patriots' man coverage, shown by the black lines, makes Tannehill pause in the pocket. This inevitably leads to a big sack for Mayo, shown in the shot below.
The first highlighted portion shows the running back blocking Scott. That allows Mayo to leave his coverage duties and blitz.
The other highlighted portion shows double coverage on Anthony Fasano. The big tight end is a smart choice for double coverage in the red zone.
Taking him away, delayed Tannehill and let Mayo make the big play. This meant Miami settled for a field goal at a key stage of the game.
Defensive backs are getting more blitz opportunities
The Patriots seem to be blitzing defensive backs more often. They did it more than once against Andrew Luck and the Indianapolis Colts in Week 11. They also tormented Tannehill with it.
In the screenshot below, the Patriots are in a standard nickel front. They are showing a basic man-under, two-deep-safeties coverage look.
The key player to notice is slot corner Kyle Arrington, shown in the highlighted portion. Arrington is disguising his intentions, but he is about to come on the blitz.
The shot below shows how the Patriots free Arrington and how Miami's pass protection fails to deal with him.
Arrington quickly makes his move and blitzes around the edge, shown by the red arrow. As he does, the safety drops down to cover Arrington's slot receiver, shown by the blue line.
The black lines indicate the man coverage behind the blitz. The Patriots have now settled into a man coverage shell with a single-high safety.
Arrington is untouched off the edge because the Patriots win up front. The screenshot below shows how.
Arrington is freed because the Patriots have drawn another double team inside. The highlighted portion shows Deaderick again occupying two blockers. The Patriots have beaten five with four along the line of scrimmage.
Arrington beats running back Daniel Thomas (33), around the corner and hits Tannehill, forcing an incompletion. Tannehill had an open receiver over the middle, but the Patriots' blitz got to him first.
In their last three games, all wins, the Patriots have used the blitz to attack opponents. They are attacking on a regular basis and often trusting man coverage behind it.
It's a risky approach and one that is departure from Belichick's traditional reliance on Cover 2, bend-don't-break schemes.
However, the new attacking mentality suits players like Mayo and Spikes. It also compensates for the lack of a true pass-rusher other than Jones, along the front.
It will be fascinating to see if this trend continues against the Houston Texans' zone-running offense this Monday night.
The blitz is helping New England's defense stuff the run and create big plays. If that combination continues, the Patriots will only be harder to beat come the playoffs.