Cleveland Brown's X's & O's: Christian Kirksey, Run Stopper

During a season to forget, third-year linebacker Christian Kirksey has emerged as the cornerstone of the 2016 Cleveland Browns defense. Join The Orange and Brown Report in the film room as we break the first-year starter's impact in the run game during last weekend's 27-13 loss to the New York Giants.

Despite being a part of a dismal defense lacking consistent playmakers, Cleveland Browns inside linebacker Christian Kirksey continues to show up for work and perform week in and out.

The Iowa Hawkeye currently sits at third in the NFL with a career-high 114 total tackles through 12 games and is the keystone of a young, hungry front seven that includes NT Danny Shelton, LB Jamie Collins (contingent on the club reaching a long-term deal with the talented linebacker this offseason), Emmanual Ogbah, and Carl Nassib.

During the squad’s week 12 27-13 loss to the New York Giants the emerging playmaker recorded 11 tackles, with many coming at or near the line of scrimmage. In fact, Kirksey’s greatest strength thus far has been his run defense, where Pro Football Focus (PFF) has graded him out at an 82.1 – an above average score on a below average defense.

Let’s go to the film room to break down Kirksey’s impact in the run game.

Good run-stop teams have one trait in common: Each member does his, and only his job. When each defender does his job, a well-designed run fit scheme will limit explosive gains on the ground. Effective run fits should look choreographed amid the chaos of an NFL play. Some players will anchor a double team. Others will squeeze a gap. Still more will attack downhill. Others flow to the ball. Someone must stay at home on the backside of the play to prevent a cutback.

Our first play illustrates this principle as Kirksey simply does his job, allowing other defenders to make a TFL.

The Giants come out in 11 personnel (1 TB and 1 TE) with an inline blocker to create a six-man line and a tailback to the right of the shotgun-aligned quarterback. The play concept is the popular gap-blocked ‘Power’ play, utilizing down blocks and a pulling guard to hit the C-gap.

The defense responds with their Nickel package (although this alignment should be considered the Browns’ base defense as the unit spends a majority of snaps in this front). Notice that the defense has six box players to the offense’s seven. This is an indication that:

  1. A safety will drop down to play a run fit
  2. A defensive lineman is playing a 2-gap technique.

We cannot see either safety from this angle, indicating that they are not part of the primary run fits as they are too deep to make a tackle near the line of scrimmage. By process of elimination, a defensive lineman must be a 2-gapper.

Focus on alignment to identify a 2-gap player pre-snap. Neither defensive end can 2-gap as both are aligned on the outside shoulders of the EMLOS (end man on line of scrimmage), while the interior linemen are in a 2i (inside shoulder of the guard) and tight 3 technique (outside shoulder of the guard). In order to play a 2-gap technique effectively, the defender must be in position to attack and cross the blocker’s face if necessary. This player appears to be #98, nose tackle Jamie Meder, although it is possible that Shelton is in a 2-gap as well.

Contrary to conventional wisdom, run defenders do not blindly run into their “assigned gap” at the snap of the ball. Gap responsibility and technique changes based on post-snap keys and type of block the defender reads.


Notice that different block types and flow dictate different responsibilities. A player may move from spill, force, or plug play-to-play against identical formations based on the offensive concept. The images above are two pages of over 45 pulled from a Dick Lebeau playbook detailing run fits against various formations, flows, and concepts. 

While former defensive coordinator Jim O’Neil was ridiculed (rightfully) for saying his defense did not have gap responsibilities, he was likely referring to the fact that a run defender’s responsibility is often fluid and will change based on keys, block identification, technique, etc. O’Neil ran – and appears to continue running – into trouble primarily because he incorporated too many ‘reactionary block’ keys, concepts, and techniques into his scheme. The idea is technically sound, as evidenced by the fact a vast majority of defenses from high school up to the NFL operate under the same philosophy. The former DC simply integrated too much detail into his system, leading to indecision, miscommunication, and poor technique due to information overload.

With that in mind, let’s break down how the Kirksey-led front six reads their keys, selects the appropriate fits and technique based on block/play identification, and executes against the Power O.

Kirksey is likely reading a ‘triangle’ key that includes the left guard, quarterback, and tailback. The defensive leader will first look to the guard for a run/pass key, reading ‘hi hat’ for a pass and ‘lo hat’ for a run.

After identifying run/pass he will then move on to block identification as this will tip the play concept and direction. Base blocks, down blocks, reach blocks, and a puller all call for a different technique. Film study and practice reps are vital to speed this read and recognition phase of the play. The quicker Kirksey determines run/pass, play type, and play direction, the quicker he can execute.  

After reading the guard Kirksey’s eyes will move to the tailback to read ‘backfield flow’, generally full or split flow.

After identifying the down blocks and tailback flow, Kirksey must execute his assignment. As the keys point towards a gap-blocked run play coming his way (the down block and tailback flow give away play direction) he will fill the C-gap, knowing that a puller will come around to replace the right tackle as he double teams #56 Danny Shelton with the right guard.

Kirksey’s job is to attack the block of the puller as he wraps through the hole outside-to-in. He wants to force the ball back inside as his counterpart, #51 Jamie Collins, should already be scraping to the ball due to his key read, the pulling left guard.

If Kirksey kicks the ball back inside, the tailback will run right into Collins just past the line of scrimmage.

While the article’s focus is Christian Kirksey, let’s take a moment to focus on the entire front six to gain an understanding of each player’s role in the run fits.

Starting on the far left, #94 defensive end Carl Nassib will play a BCR (bootleg, contain, reverse) rule on flow away. His job is to attack the right tackle while remaining parallel to the line of scrimmage. He will play the quarterback bootleg on any play action concept, maintain the backside edge of the defense if the ball carrier cuts the ball all the way back, and stay home for a potential reverse to the wide receiver. He must not get too far up field or pinch inside while playing his role, otherwise the ball could cut back outside.

Ideally, nose tackle Jaime Meder will attack and work overtop the center’s down block to provide lateral flow to the ball. He is a ‘pursuit player, meaning he should chase the ball carrier from inside-out.

Shelton has the toughest job, anchoring and splitting the guard/tackle double team. He needs to prevent the blockers from achieving an easy ‘jump through’ to the scrapping Collins by attacking the base block with his hands, swimming his hip into the B-gap, and dropping the right leg to create a strong anchor point. By creating an anchor point, he ensures that Collins has a free run to the ball as the guard or tackle want to move off the double-team and climb to the scrapping linebacker.

Like Meder, the former Huskie is a ‘pursuit’ player, attacking the ball inside-out.

Right defensive end Emmanuel Ogbah will face a kick-out block from the tight end. The tight end must widen out Ogbah to create a C-gap hole for the tailback. Ogbah wants to do the opposite; attack the blocker and force him to give ground in order to squeeze the gap, reducing its width while also playing ‘force’.

The force player must push the ball back inside to the spill players and secondary fills. There are many techniques used to pay force, but as a general rule the defender must keep his outside shoulder and arm ‘clean’ by fighting with his hands to prevent the blocker from getting into his body.

The final piece of the puzzle is Kirksey’s fill.

Notice how quickly he reads his key, recognizes the play, and comes downhill to fill. We see a violent attack on the puller’s outside shoulder at the line of scrimmage, forcing the ball carrier to plant and cut inside towards the pursuit.

The defense ends the play with five players surrounding the ball carrier from three sides, (left, right, and heads up) leaving him nowhere to go.

This is the choreographed dance of run fits and demonstrates exactly why the concept of ‘gap responsibility’ is often misunderstood. Image what would happen if Collins blindly attacked his initial assignment, the backside B-gap.

If the defensive tackles and Kirksey cannot get the ball carrier to the ground at the line of scrimmage (not his job), there is no second-level player to make the tackle. Now the defense is looking at a tailback on a safety in the open field - a scary proposition on this team.

Our next two plays look at similar concepts to demonstrate Kirksey’s play-making ability as he not only executes his assignment (filling on a lead blocker), but also makes the tackle.

Focus on Kirksey between the left guard and left tackle. The play concept is the gap-blocked ‘Iso weak’, in which the fullback will ‘isolate’ Kirksey with the tailback fitting off the block.

Again, Kirksey reads his key, identifies the play, and violently fills. He attacks the blocker’s outside shoulder, forcing the ball carrier back inside to the pursuit and manages to make the tackle.

Although the offense did gain five yards on the play, the tackle was important because the nose was unable to prevent the left guard from climbing to the scraping Collins. If Kirksey doesn’t make the tackle the free safety would likely need to get in on the play (again, a scary proposition).

Every week Kirksey shoots a gap to make a highlight reel TFL. While it may look like he is freelancing, he is in fact following a set of prescribed rules, again based on keys, formation, and play call.

In our next example, we see Kirksey shoot a gap to run down the ‘Power’ concept from behind. This play illustrates how run fits can change simply based on formation and the defensive call.

Recall the first play we analyzed.

The backside linebacker (key the pulling guard) was responsible for fast flow overtop the defensive line to the ball. The play-side linebacker was responsible for filling the hole against the puller in order to force the ball back to the scrapper.

 After breaking down the defensive responsibilities we noted:

“This is the choreographed dance of run fits and demonstrates exactly why the concept of ‘gap responsibility’ is often misunderstood. Image what would happen if Collins blindly attacked his initial assignment, the backside B-gap.

If the defensive tackles and Kirksey cannot get the ball carrier to the ground at the line of scrimmage (not his job), there is no second-level player to make the tackle. Now the defense is looking at a tailback on a safety in the open field - a scary proposition on this team.”

So why does Kirksey contradict the previous statements by shooting the backside B-Gap?

It all comes down to the safety.

Notice that free safety Ed Reynolds (#39) has dropped inside the right defensive end.

Reynolds is now in position to become part of the run fits, although ideally he would be 1-2 yards closer to the line of scrimmage. This is likely a coaching decision to ensure that he can play his pass responsibility if necessary. By “cheating” him back a few yards, coaches are minimizing the distance he must cover if he has any intermediate/middle hole responsibility.

Kirksey is running one of two defensive calls here:

  1. He is run blitzing regardless of run concept/direction and will peel off to guard the tailback if the play is a pass.
  2. Kirksey can read the backside gap to shoot a “clear” look while scrapping if the look is “murky”

In either defensive call, Reynolds will base his fit on Kirksey’s path to the ball. The safety’s job is to “make” Kirksey right by:

  1. Playing the backside gap if Kirksey scrapes
  2. Flowing into the box towards the point of attack if Kirksey shoots the gap

Keep in mind that this play is designed to hit the C-gap inside the tight end.

Notice how the linebacker pops his feet and gets a great jump on the snap. If Kirksey had the option of shooting a clear gap, the decision is obvious as the departing guard leaves a hole several yards wide.

Reynolds pauses long enough to read Kirksey’s fit and then folds into the box, although his secondary run support is unnecessary.

The entire defensive line does a great job of reading, recognizing, and reacting to the play. Meder does a great job attacking the center and crossing his face to the ball, Shelton anchors the combo block from the left guard and left tackle (which keeps the linebackers clean), and Nassib squeezes the C-gap by attacking the tight end while also working his outside arm free as part of his force responsibility.

Rather than charge head first into a muddied gap, Collins holds his ground as Meder, Shelton, a Nassib have eliminated the play’s aiming point.

The lack of a clear gap prevents the tailback from “pressing the hole”, allowing Kirksey to run him down from behind and make the TFL. Kirksey can make this play – and Horton can make this call – due to great anticipation and closing speed.

The beautiful part of this play is that even if the offensive line had won the C-gap, Collins would have filled against the pulling guard outside-to-in, forcing the ball back to Reynolds, Meder, and Shelton.

With the offense is disarray, young players along the front seven likely offer the best mix of growth and play-making ability. The 2016 season has been a brutal watch, but the young talent along the defensive line and in the linebacker corps has incrementally improved week to week. Because the defense is still several bullets short of a full clip, the progress often doesn’t jump out of the screen, but it is there. A legitimate pass rusher, safety, and cornerback would do wonders for the unit. In the meantime, Browns’ fans will have to accept small individual victories s over the final four games because this team is as far from contending as it gets.

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