Decoding Diaz: A Research Report

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By Scott Gerlach (LonghornScott), Special Contributor
Posted May 8, 2012
Copyright © 2019

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Defensive coordinator Manny Diaz

Manny Diaz oversaw one of the best defenses in college football last season. But how does Manny do what he does? In part one of his step-by-step breakdown, Scott Gerlach goes inside the Diaz defense and shows how the 2 Read system operates.

I know I’ve been away for a while but I haven’t been completely idle. I had already planned on spending some time with the defense this offseason.  Then during spring ball, Jesus, Eric and I had a few chances to meet up and those conversations (in particular some key insights they were able to offer through one of their sources) prompted me to delve deep into our defense and I’m only recently coming up for air.  I’m getting to a point now where I think there is some valuable and appropriate insight to share and I thought it’d only be to right to share it with this community since the inspiration originally came from the guys here.  These reports are going to be fairly technical in spots where I feel like we are hitting on concepts that haven’t already been widely discussed, but hopefully we won’t lose the big picture in the process.  I should point out that this is based on my own research, film watching, reading, and speculation.  I’m definitely not right about every detail herein but hopefully this will serve as a primer for more insight and discussion about the truly exciting defense that is building in Austin.  I welcome comments, questions, and clarifications.

Decoding Diaz: A Research Report

The modern college offense is so multiple through formation and dynamic with motion that it’s absolutely essential that the defense’s core concepts allow them correctly align and assign their responsibilities against anything that the offense could throw at them.  Ultimately, that means that the defense must operate based on simple rules of identification and have the flexibility to respond to motion and still stay sound. 

The real trick for the defense is developing a method of doing that without revealing the defense pre-snap and giving the offense a chance to target them.  In a world where both teams have to react to each other post-snap, the defense will have the advantage in athleticism (particularly with Texas athletes).  And although we all love Manny’s penchant for one liners, it’s Diaz’s ability to disguise his defense and give his players simple adjustments to motion and formation that allow him to feature his athletes in so many different blitzes.  Make no mistake, the exclamation point of Diaz’s defense is the focused pressure that attacks protections and blocking rules, but Diaz gets there by layering his coverage concepts in a way that makes it difficult for the offense to know where to attack.  There are several ideas that form the basis for Diaz’s disguises and probably the most important is the 2 Read defense.

The 2 Read Defense

The 2 Read is a pattern reading coverage concept that adapts itself based on offensive formation and route threats. That is, based on the number of detached receivers to one side of a formation, the 2 Read can adjust from providing run support from the corners like traditional cover 2 to sinking with multiple vertical routes like quarters coverage.  What’s more, the 2 Read behaves as a split coverage when playing over the top of multiple vertical threats to one side of a formation (like quarters) and playing hi/low on a single vertical threat to the other side (like cover 2).  Sounds complicated, but it doesn’t have to be.

Responding to Offensive Threat

Most defenses identify formation by how many detached receivers (i.e. not hugging the offensive line) they face to each side of the formation.  The reasoning is that each detached receiver represents an immediate vertical route threat that a sound defense must have a plan for.  The 2 Read philosophy is to always have a deep defender for each vertical route from the offense but to avoid over committing to deep zones.  This has a number of benefits when compared to a traditional man or zone that we will try to explore as we go through the various machinations of this defense.  With that said, let’s take a look at how 2 Read adapts to the offense before and after the snap.  

Each of the upcoming diagrams will account only for half of the defense and offense because that is the best way to conceptualize this defense initially.  Traditionally, the defense is thought of as strong or weak, but Diaz sets his coverage based on the ground it has to cover.   Think of the secondary defenders as being split into two groups: the field corner, field safety, and sam linebacker form one group while the boundary corner, boundary safety, and will linebacker form the other.  The mike linebacker is the swing man that unites the two tribes against the offense.

Within these groups the alignment and assignment in the 2 read structure is handled on the fly (as we said, this is based on the number of detached receivers presented by the offensive formation).

None Detached

If the offense presents no detached receivers to one side of the formation, the corner will squeeze in to align just off the end of the offensive formation and enhance his role as the force defender (when the corner is a force player for the defense this is generally referred to as Cloud support). 

Since the offense is not presenting an immediate vertical threat to this half of the defense, the corner will align in the most advantageous position as the force player where he can aggressively attack any outside running threat.  Meanwhile, the safety and outside linebacker still give the defense a 2 to 1 advantage versus routes from the tight end.

One Detached

With one immediate vertical threat the defense will respond with a cover 2 Cloud look (again the corner is the force player against the run).  The corner and linebacker are each responsible for an underneath zone: reading for a run, rerouting the first receiver through their zone, and sinking below vertical routes forcing the QB to throw over the top.  This delivers any deep threats to the safety who will deny the vertical portions of receiver routes and position himself split multiple vertical threats and break on the ball.

Note that the defense has aggressively addressed vertical threats, maintained a 3 to 2 coverage advantage, and has an immediate presence against the outside run.  So here, where quarters coverage can often be susceptible to play action or can be forced to give up easy throws to the flat, the 2 read maintains the underneath advantages of cover 2 and keeps its deepest defender out of run/pass conflicts. 

Two Detached

It’s at this point that we see where the 2 Read gets its moniker.  Against two vertical threats the corner and safety will key the #2 receiver to their side of the formation (i.e. they will read #2), while the linebacker will behave as a coverage wall, trying to disrupt any routes breaking to the inside and playing the first force against the run.  

The “read” on the #2 receiver is not as complicated as you might imagine, it’s really just a way for the defense to stay over the top of the two receivers in man coverage while avoiding some of the pitfalls that can go along with that.  From the defense’s perspective there are three things that can happen in the first 5 yards of any route combo: the #2 receiver goes in, the #2 receiver goes out, the #2 receiver goes vertical.  All the 2 read does is base the coverage responsibilities on that initial stem.  Somewhere Pavlov is ringing a bell.

#2 breaks in

When #2 breaks in the corner knows he’s essentially playing soft man coverage on #1.  The outside linebacker (or nickel back) will try to reroute #2’s route without over committing.  The goal here is to disrupt the drag route from the offense without giving away the field flat (which is where spread offenses often try to pick up easy yards).  Meanwhile, with the second vertical threat vacating, the safety will keep depth initially and look for work down the vertical pipe in front of him.  He especially wants to be aware of deep posts from #1 and crossers from the other side of the formation (the Mesh passing concept utilizes two crossing routes that basically allow the receivers to set picks on the underneath coverage).

#2 breaks out

On an outward stem from #2, the corner and safety essentially exchange their vertical responsibilities.  This allows them to take advantage of the positioning they already have, giving them leverage on both the routes from the offense.  One detail that’s important is that on a vertical route from #1 with #2 breaking out, it’s crucial that the corner carry and deliver the deep route from #1 first.  He’s going to position his body in a way that allows him to backpedal while reading the QB and keeping #1 in his peripheral vision (this is often referred to as “reading the triangle”).  That will allow him to gain depth and deny a throw to #1 but also give him a quick break on a throw to #2’s outside route.

Another important concept that involves an outward breaking route from #2 is the bubble screen.  I think of the bubble as essentially a running concept against the outside coverage.  In most spread offenses it acts as a complement to the zone running game which allows the offense to apply quick pressure inside or outside of the outside linebacker and defensive end and it’s especially effect as a way to punish soft coverage on the outside (soft man or 3 deep).  This enhances the run game, especially for offenses that can utilize read concepts to neutralize either the outside linebacker or defensive end.  Note in the following diagram how the 2 Read structure gives the corner a leg up against the bubble screen because he is reading #2 at the snap.  This allows him to attack the block from #1 and prevent the offense from getting outside leverage, stringing the play out and giving the rest of the defense the opportunity to flow to the ball.

One of the major strengths of the Texas defense last year was the aggression and tackling from the cornerback position, especially against the screen game.  That took away one of the essential ingredients that many spread offenses rely upon to keep them on scheduled downs and allowed our box defenders to play the run without the fear over losing leverage on the outside.  It also gives you some insight into why the 2 Read alignment structure is an effective disguise for some of the other concepts in the Texas defense.

#2 goes vertical

When #2 stays vertical through the first portion of the route, the safety is responsible for his route and the corner will stay on top of #1.  Traditionally, one of the most successful passing concepts against cover 2 defenses (which 2 read is often confused for) is an underneath route by #1 with a deep corner from #2 (this is often referred to as the Smash concept).  The idea is to hold the corner shallow, allowing the offense to isolate one of their fastest players (the slot) deep against the safety or take easy pickings on the underneath route.  The advantage of 2 Read here is that all three defenders are the same page and the safety knows that he is only responsible for the vertical from #2 after the initial stem (unlike cover 2).  That allows him to maintain spacing and leverage and force a much more precise throw from an offense that hopes to victimize him.

So that’s the basics of the 2 Read defense:  Split the field into two parts, identify the vertical threats, and use the most appropriate response from a 2 deep shell.  By mixing and matching these half-field coverages and using alert calls to help the opposite side of the field in the case of motion, the defense can essentially operate in two split coverage teams and deal with most of the threats that the offense can throw its way.  But what happens when the offense presents more than 2 detached receivers?

Since there is so much detail to explore with the 2 Read coverage and it’s a concept that is largely foreign to most fans, we’re going to break it into two parts.  We’ve already seen in the basic structure of the 2 Read how it expands with the offensive passing threats, absorbing some of the advantages of man, cover 2, and quarters without completely committing to any of them by splitting the field and balancing the threats on each side.  In our next installment we’ll take a look at how 2 Read responds to unbalanced passing threats, the mike’s role in this defense, and some of the ways that the 2 read can be attacked.  Until then, hope you enjoyed.

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