2015 Bills Defensive Study: Secondary


The offseason begins by evaluating your team. The defensive backs were a bright spot in 2015. Only a few tweaks are needed. Those tweaks may need to be at the safety position.

Going into training camp the whispers were that the defensive secondary were possibly the weak link of the defense. Many people believed that their great play down the stretch in 2014 was a result of the stellar play of the front four. There was some truth to that, but the actual whispers were due to injuries.

Three of the four starting defensive backs were dealing with injuries. Leodis Mckelvin, Stephon Gilmore and Aaron Williams all had missed time in the spring which caused many to worry about how the defensive backfield would look come game one of the season. The Bills used a second round draft pick on Ronald Darby, but he was expected to be brought along slowly due to the stress that this scheme puts on corners. The other player in question was Corey Graham. He started his transition to safety in 2014 and was expected to play safety in 2015. The loss of Da’Norris Searcy to the Titans left a hole at the safety position with no idea on who would secure the starting spot. So many pieces of the secondary were in question to start the season.

It is crazy to look back and realize where the secondary began and how they held up throughout the year. The first game of the season saw Darby and Gilmore starting at corner and Graham and Aaron Williams at the safety positions.

The secondary really played well in the Bills first game against the Colts. With the help of some tremendous pressure calls against Andrew Luck, Darby and Aaron Williams each had interceptions and they helped hold Luck to five yards per pass attempt. But the theme of the 2015; injuries, began in that game. Safety Corey Graham was injured after one play and he missed the whole game, thrusting Bacarri Rambo into a tough spot. He held his own and the Bills got the win at home.

Over the course of the season the Bills lost Darby and Gilmore for certain stretches but overall they were the cornerstones and play-makers in this defense. By seasons end Darby and Gilmore were rated 9th and 20th respectively at their positions per Pro Football Focus (PFF). They also were top ten in pass deflections, Darby was ranked 5th with 13 and Gilmore was ranked 8th with 12. So for most of this study they won’t be the focus. I want to focus on the weak points in the secondary and it is safe to say that they weren’t part of the problem.

The Bills struggled in the pass game. The Bills allowed 249 yards a game through the air which was ranked 14th in the league. The Rex Ryan defense gave up the third most 20+ yard receptions in the league which is not typical of this scheme. Fifty nine 20+ yard completions are morale killers. Part of the reason that the Bills gave up 22.4 points a game was because they allowed the 5th most touchdowns in the passing game by allowing a total of 30 touchdowns.

The Bills had issues in the slot. Nickell Robey was targeted the 6th most and allowed the 6th most in receptions on the year. What really killed the Bills defense is how many yards he gave up on those receptions. When teams completed passes versus Robey they gained an average of 11.76 yards a completion. Corey Graham was even targeted when he dropped down into the slot during a few games where the Bills stayed in their base packages. Opposing offenses having that kind of success versus your nickel corner creates many issues in this scheme. The defensive scheme already surrenders a lot of plays over the middle, so having a slot corner that struggles increases the likelihood that teams will attack that very same quadrant of the field.

Per Pro Football Focus Per Pro Football Focus

Without question the biggest issues in the secondary occurred at the safety position.

Safety Play

Like every position on the Bills in 2015, the secondary was marred with injuries throughout the season. The biggest loss in the secondary was Aaron Williams. In the second game of the season he went down with a neck injury and was out until the week five game against the Titans. He had another scare in that game and didn’t play the rest of the year. Losing a leader and intelligent player like him hurt the communication in the secondary.

Safeties play a critical role in both the pass and run game. Specifically the strong safety position. Aaron Williams started the season as the strong safety. In this defense the safeties must be able to tackle. In the first two games that Aaron played, teams attacked the Bills defense mainly through the air. So his value versus the run was tough to measure. According to Pro Football Focus (PFF) he was only in on 47 run snaps, 12 of which he was lined up within 8 yards of the line of scrimmage and he recorded 4 tackles and 3 stops in the run game. When you look at his snap numbers below from 2013 and 2014, Aaron showed mixed results when asked to be a key cog in the run defense. The statistic of being within 8 yards of the line of scrimmage usually means that the defender has a responsibility in the run game. In Rex’ defense that is usually but not exclusive to the backside C gap. Aaron was asked to be run support on 226 snaps in 2013 and 118 snaps in 2014. The only productive year was in 2013 where he made a significant difference in Pettine’s defense, he made 6 stops which ranked him 6th in the league. PFF considers stops a “loss” for the offense. Based on William’s 2013 numbers I expected him to be a key contributor in this years run defense. He is a guy that is a really good tackler and hitter.

Per Pro Football Focus Per Pro Football Focus

Once Aaron went down, Graham did a very good job against the run. If you look at the chart above, you can see Graham was asked to be within 8 yards of the LOS 105 times versus the run. That ranked him 3rd most in the league. Malcolm Jenkins led in that category with 171 run snaps within 8 yards of the LOS. Graham led the league in tackles from that standpoint and also in stops. That is pretty impressive considering that he played corner most of his career.

Graham did a tremendous job versus the run this year, he definitely surprised me in that department. He only missed one tackle on opposing running backs.

In the pass game Aaron struggled in the three games he played in. You can tell he was still learning the system just like the other players.

In the three games that he played in, Aaron was targeted 10 times and he allowed 8 receptions. The total yardage gained was 82, but he also gave up 3 touchdowns. One touchdown to Dwayne Allen and two touchdowns to Julian Edelman, one of which was the play that he got injured on. He really didn’t give up that much yardage after the catch so they weren’t big plays. The longest touchdown given up was the 22 yarder to Edelman.

In 2014 Aaron Williams was targeted 30 times and allowed 20 receptions for 231 yards surrendering 1 TD and intercepting 1 pass. In 2013 he was targeted 53 times and allowed 31 receptions for 303 yards, 2 TDs and 2 INTs.

Based on the way he started in 2015 and his prior years in a 4-3 defense last year and a 3-4 defense in 2013 I think that Aaron may have struggled this year versus the pass. How much? I don’t think he would’ve struggled as bad as Rambo and Graham did…

That is where the loss of Aaron hurt the Bills in my opinion. I don’t think I am going out on a limb when I say that Aaron is more talented. Heck just his age could’ve been the difference. I could argue that Graham wore down later in the year. I just think that if Aaron was in on defense he would’ve been a little better in pass coverage than Graham and Rambo especially in man to man coverage. Look at these stats below.

Per Pro Football Focus Per Pro Football Focus

Graham absolutely struggled in the passing game. He had the 8th most targets at the safety position and allowed the 8th most receptions. Grahams lack of speed and agility contributed to him giving up 549 yards to opposing receivers when he was the primary man in coverage. Both he and Rambo surrendered 10 TDs between them. That means 1/3 of the TDs that the defense gave up through the air can be attributed to those two players. Add the TDs given up by limited action players like Aaron Williams and Duke Williams and the number rises to 14!!! The numbers show that the safeties were indeed the weak link on this defense. Teams knew that and they attacked that position consistently.

The Bills have very good corners which is key because they are the play-makers in the pass game. Rex Ryan likes to create pressure in order to force the ball out so that the corners can jump the routes. With that position one of the strengths of this team the Bills need to get better play from their safeties. Those guys are asked to cover a lot in this defense. Hopefully getting Aaron Williams back will help, or maybe they can address it in free agency or the draft. But without a doubt, the Bills need to play better at the safety position if they want to be better on defense.


The Rex Ryan defense like many other defenses in the league is a multiple defense. When you are a multiple defense your roster must be comprised of players that can think on their feet. A safety may be 20 yards deep on one play, the very next play he may be run support and the next play he may be aligned on a slot wide receiver. When you are in this kind of defense you have to know just about everyone’s responsibilities on any given play, because it is a defense that relies on intelligence and discipline. As I have said before the offense may come out in 21 personnel formation, with a 2×1 set- 2 receivers to one side and 1 to the other. But if one of those WRs motions to a twins set, the defense must know the proper procedure to carry out the same play with a different alignment. Check out the minor changes that occur when a player motions on this “under bee sting” play-call.

Larry is the passing strength call. The defense has to check to Rob because of the motion, now there are two WRs to the right. The left corner now rolls up, the $ drops down to cover the Z, and the other safety slides over to cover the middle 1/3. We call this a safeties over play. The corner did not go with the motion, that would be called a corners over play. Teams will decide on if they want the corner to motion or not based on game-plan. The same play is being executed, but because of the motion, assignments by a few players change. This is a simple example of adjustments that need to be made on defense. Taken from Rex' 2010 playbook. Larry is the passing strength call. The defense has to check to Rob because of the motion, now there are two WRs to the right. The left corner now rolls up, the $ drops down to cover the Z, and the other safety slides over to cover the middle 1/3. We call this a safeties over play. The corner did not go with the motion, that would be called a corners over play. Teams will decide on if they want the corner to motion or not based on game-plan. The same play is being executed, but because of the motion, assignments by a few players change. This is a simple example of adjustments that need to be made on defense. Taken from Rex’ 2010 playbook.

So certain checks need to occur, the defense must be “reloaded” and set with everyone being on the same page. You can imagine the communication and hand signals that need to occur just to run a defensive play. The Bills had too many breakdowns at the safety position this year. You think new assistant DB coach Ed Reed can help with that? Some of the breakdowns were due to coaching/scheme and some were just flat out not executing a play-call. Before you judge the result of a given pass play, try to examine why the player did what he did within the scope of the defensive scheme. So lets dive into that.

Rex Ryan likes to have a secondary that is fluid. By that I mean he wants the secondary to be able to adjust to certain formations and adjustments all while keeping the defensive front consistent. He likes to have the secondary to adjust, like in the play above. Rex doesn’t have the corner go with the motion because then the defense would be outnumbered to the tight end side in the run game. It’s a pretty simple game of, don’t get outnumbered or outflanked. Offenses are always trying to get an edge, or an advantage by moving players around.

The Bills secondary primarily utilizes a concept called the read concept. It is a style of play that is typical of many defenses in the NFL. It is different than what you may have learned in high school. When your coach used to constantly call cover three, you would normally align 7 yards off the WR and then back-peddle to a certain landmark. You had to get to a certain zone and make a play on the ball when someone entered your zone. The read concept is a little different. It is still cover three, but now as the corner you are taught to read the #2 WR. That WR’s route will determine who the DB will cover.

Offenses typically like to run routes in combinations. They will pair two routes with the goal of beating a certain coverage, so there are man and zone coverage beaters. Probably the most common route combination is the curl/flat combo. In a defense like the Bills, the corners and safeties must know the common route combinations, they must be able to recognize them immediately because who they are going to cover hinders on them diagnosing it correctly. If the #2 WR is running a flat route then the corner should be expecting a select few routes to complement it. Such routes as a slant, vertical or curl route. That is how they diagnose a play. So the typical coaching point in read concepts are that the defensive backs are reading the #2 WR. If the #2 WR runs a vertical route, the corner glances to see what the #1 is going to run, if he looks like he is going to break in or out he will run deep with the #2. In an event that the #2 runs a flat route, the corner should expect a curl route or one of the other complementary routes so he should jump the curl route.

So a simple cover three read play-call could have the defensive back covering a different WR from one play to the next because it is predicated on the routes of the WRs. As you can imagine this kind of technique takes practice and film study to master. You can run read concepts out of single high safety or double high safety alignments. When you have double high safeties, cover four is the common read concept. The Bills run a lot of cover four read concepts. Cover four looks like this:

The safeties read the #2 WRs. If #2 doesn't threaten his 1/4 of the field he then helps the corner out with #1. The CBs are also reading #2, if that player breaks in or out the corner takes #1. If the #2 runs some sort of vertical route, the corner must diagnose/determine the intentions of the #1 WR. Is that WR going to run deep also? Or break his route off? If the #2 runs and in our out those zones will be covered and the safety and corner can now double the #1, which more than likely will be some kind of deep route.

The safeties read the #2 WRs. If #2 doesn’t threaten his 1/4 of the field he then helps the corner out with #1. The CBs are also reading #2, if that player breaks in or out the corner takes #1. If the #2 runs some sort of vertical route, the corner must diagnose/determine the intentions of the #1 WR. Is that WR going to run deep also? Or break his route off? If the #2 runs and in our out those zones will be covered and the safety and corner can now double the #1, which more than likely will be some kind of deep route.

Check out this cover four read concept below that that did not work against the Redskins.

The motion causes confusion because the DBs are unsure of what WR is the #1 or #2. Graham sees the #2 run a vertical route to the middle of the field so he takes the receiver. Leodis let the #1 WR get the leverage on him from the snap. So before you know it, the #1 is running through Mckelvin’s zone, gets the leverage to the post for a TD.

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The Bills have two corners that are really good at read concepts. Obviously they were not playing in that Redskins game and it was noticeable. But Darby did a lot of this at Florida State last year, probably one of the reasons the Bills were comfortable drafting and playing him early. But the safeties have had trouble with this kind of coverage. They have been slow to read the routes, putting them out of position on the wide receiver. Like the following play by Graham:

This is a cover three read concept. Graham is reading the #2-TE. It is a tough read because the #1 and #2 are dead even running vertical routes. The #2 breaks to the sideline, so Graham is supposed to stay over the top. By the time Graham realizes that he is supposed to be bracketing the #1, he is out of position. This is a play (#11) where the scheme created a coverage issue due to the read concept.

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If you look at the chart below you will see some of the reasons why the safeties gave up 14 touchdowns this year. Find the column that is titled Zone, on TD #11 you will see the safety struggled with the read concept so I labeled that 1M because it’s not quite zone or man. All 14 TDs are on the chart. The WR surface means how many WRs are to each side. The personnel is how many RBs and TEs were on the field. For example 21 personnel is 2 RBs, 1 TE and 2 WRs. The column labeled scheme are plays that put the players in certain positions or play-calls that caused the defender to blow the coverage. Such as a double team on Gronk in a goal-line situation on play #3. On that play, Rex called a double team on Gronk, but the offense shifted, (which caused a change to the defender’s assignment) and it caused the defender Duke Williams to be confused. So although the play-call was good, the motion by the offense created confusion. Therefore the problem on the play was created because of the scheme AND the lack of execution.

Here are each of the plays if you want to view separately or view all 14 plays as one in youtube video below. #1, #2, #3, #4, #5, #6, #7, #8, #9, #10, #11, #12, #13, #14 Here are each of the plays if you want to view separately or view all 14 plays as one in youtube video below. #1, #2, #3, #4, #5, #6, #7, #8, #9, #10, #11, #12, #13, #14

After looking at the chart you can see that a majority of the touchdowns came out of the 2×2 WR surface with 11 personnel. The Bills and Rex Ryan did not match up with 11 personnel the same every week because each teams personnel are different. But 4 of the 14 plays can be attributed to the scheme. The two plays that I didn’t discuss that resulted in TDs due to the scheme are #9 and #14. In play #9 the defender’s assignment changed because of the motion, and it resulted in a late reaction by the defender. Corey Graham and Nickell Robey were in a pattern reading concept, Robey passed the WR on to Graham who was completely burned by WR Hurns. In play #14 the Bills blitz the nickel corner and the safety did not realize his responsibility until it was too late and he blew the coverage. Watch all of the clips in one place below:

[youtube https://www.youtube.com/watch?v=h5rkUXOqxPk&w=480&h=270]

Like most defenses, the Bills have automatic checks or audibles when certain alignments or formations are presented by the offense. Now there are game-plan checks and play-book checks. Game-plan checks are self explanatory, based on your opponent’s tendencies you may install specific defensive plays to combat it. Play-book checks means that on a specific play in your play-book, if the offense aligns in a certain formation I.E. a WR surface such as a 3×1, your defense may automatically check to a certain coverage. That is what happens in the following play.¬†Lets break down play #7 against the Giants.

The defense is in its base personnel vs. the Giants 11 personnel, which some would say is a mismatch. Yes, it probably is but the no huddle offense caught us in base personnel so the defense calls a play titled Rush Raider (seen below). But if the offense aligns in a bunch or 3×1 WR surface, as you can see in the coaching points below, the defenders are supposed to “Check Cloud’. So the “Check Cloud” is an automatic formation check.

Taken from Rex' 2010 playbook.

Taken from Rex’ 2010 playbook.

‘Check Cloud’ is an automatic coverage audible. It tells the corner to the bunch side to squat and take the short flats and the safety will take the deep 1/3 behind him. The raider portion of the play is where the backside corner is automatically put into man coverage versus the X. The other safety (Rambo-circled) then slides to cover the middle deep 1/3 of the field. The defense is in good shape. They got the right call versus the offensive look. Teams have automatic coverages, checks and audibles to get into plays that are in their favor.

As you will see in the video the play-call is pretty good. It is a four man rush, four underneath, three deep zone coverage. But Rambo is late to his landmark zone and does not get over in time to stop the skinny post right through his zone by WR Harris.

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After watching all of the touchdowns given up I started to ask myself was the problem the personnel? Are the safeties we have on our roster good enough to play in this scheme? How do their numbers compare to the safeties that Rex had in prior years? Lets take a look at those questions.

The total TDs given up by Safeties in Rex’ scheme while in NY from 2009-2014: 0,5,1,5,6,10. So it is safe to say that the Bills safeties struggled in this scheme versus the pass in 2015. The chart below doesn’t have every single safety that played on that years team, only the significant players.

Per Pro Football Focus Per Pro Football Focus

As you can see our safeties were liabilities on our defense this year. Graham was targeted as many times as both of our safeties were combined last year. Graham allowed the most touchdowns by a safety and Bacarri Rambo tied the most TDs given up by a Rex Ryan led defense spanning 2007-present.

So where does that leave us? It is readily apparent that the Bills safeties struggled when opposing teams passed the ball. Allowing 14 TDs out of 30 total passing touchdowns is a haunting statistic. Many fans believe that the scheme caused all of the issues this year. Once you analyze the secondary, specifically the safety position, I believe you can conclude most of the blown coverages that led to touchdowns were due to lack of execution. Can the Bills go on with Corey Graham and Bacarri Rambo playing significant time if Aaron Williams decides to hang it up? I don’t believe so, I think Rambo has the physical talent to develop into a decent middle of the field safety. He has the speed to cover the entire field, that doesn’t worry me. But does he have the where with all to learn this complicated scheme? Does he have the ability to cover one on one when called upon?

As good a strong safety Graham was when near the line of scrimmage, teams found ways to get him matched up in one on one situations. Graham was absolutely exploited quite often. He is a smart defensive back. Who knows where this defense would have finished if he wasn’t the back-up to Aaron Williams. But I don’t believe that he is someone that can be counted on as a starter if Aaron Williams retires.

Many fans think that Leodis Mckelvin can make the permanent switch to safety. I am not one of them. Primarily because he isn’t a good pattern reading defender. He is a good man to man defender. The kind of guy that you tell “go guard that wide receiver” and he will do a decent job unless it is a double move. But as far as making a permanent transition to safety, I don’t think he can and he is not worth what the Bills are paying him. He will need to restructure or he will be shown the door.

The Bills may need to look at some modest free agency targets who may have played in a similar defense. Or they could draft a play-maker in the upcoming draft. It is a risky move but Rex did it with Calvin Pryor and as you can see from the chart above, Rex did a good job of hiding the young player.

With all of the breakdowns in the secondary that occurred this year it doesn’t mean that these players can’t bounce back. Maybe having the off-season to study the play-book and getting the reps will help these players get more comfortable in the scheme. There are some coaching changes currently happening too and that could help boost their football IQ and their ability to succeed in this scheme. Adding Ed Reed as an assistant may look like a PR move but after studying this group, I think it is a fantastic addition by the organization. Adding a former player who has played in this defense, who knows this defense extremely well is a no brainer. Ed will know each and every check, audible and look that these players will see. On Sundays when the offense is attacking the secondary in a certain way, who can help recognize it and make the necessary adjustments? Ed Reed. Reed will also bring a calming influence to this secondary. He is a natural leader and that kind of aura will cause this secondary to gel, and maybe even become leaders themselves.

As bad as things looked on defense this year, the mistakes are correctable. All is not lost like some Bills fans may think. This secondary at times played very well, but other times just had too many mental mistakes. But a few tweaks to the scheme, some more studying and a few players added and this group can be the play-makers that this defense needs in 2016.