Teaching Defensive Structures: RPOs
RPOs have nothing to do with conflict defenders.
This is a mammoth of a post — it ties the previous posts on numbers, space, and leverage into one conversation: RPOs.
View the pre-cursors here:
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A strong understanding of defensive structures is essential to running RPOs effectively. Over the past month, we’ve looked at three essential elements of understanding defensive structures: numbers, space, and leverage. How a QB works through RPOs reveals his understanding of these three elements.
RPOs are better understood in the context of numbers, space, and leverage as opposed to “putting a defender in conflict.” Instead of thinking of putting one singular player in a run-pass conflict, what if you taught and understood RPOs as using the defense’s leverage against them by giving the QB the option to run or pass?
Another way to think about RPOs is that they solely exist as a mechanism to prevent the offense from running against a box where the defense has a numbers advantage. In other words, RPOs are not about putting the defense or defenders in conflict, but about accounting for numbers in the box. Then, if the defense is +1 in the box, the offense relies on leverage to attack space in the pass game.
Additionally, RPOs are an available tool to attack defenses that give up too much space in the passing space on a called run play. In other words, it allows the offense to attack defenses who are playing with poor space control (bad leverage) in the passing space even on a run play where the offense has a numbers advantage.
This post will go over three types of RPOs to illustrate these points:
Post-Snap First Level RPOs
Post-Snap Second Level RPOs
Post-Snap Third Level RPOs
In sum, this post will argue that RPOs solve a numbers problem by attacking space using leverage advantages rather than putting defenders in conflict.
By looking at each type of RPO, we will uncover each element (numbers, space, and leverage) to see how they play out in real life examples.
First, we must go over what a sound defense looks like and demystify conflict defenders.
Understanding Gaps and Conflict (The Numbers Problem)
The first thing we must go over is how offensive formations dictate the number of players a defense must have in the run fit so the defense is +1 in the fit. The defense, quite simply, needs to have as many defenders in the run fit as gaps the offense presents. Starting in 10 personnel, the offense shows six gaps and thus requires the defense to account six of their defenders for the run fit to be sound. Any added blocker (11 personnel, 12 personnel, 20 personnel, etc.) will add another gap and thus require the defense to add one more defender to the run fit to be sound.
The defense has issues being +1 out of a two-high defensive structure (MOFO) for one simple reason: space. While the defense would like to have their inside linebackers in the run fit, offensive formations sometimes push inside linebackers out of the box to cover down on a receiver.
Here’s a video example of this pushed-out Mike having issues in a two-high structure against trips (source):
A defense then might ask that red inside linebacker in the drawing and the linebacker in the blue box in the video to play both the pass and the run, but this rarely if ever works. A sound defense wouldn’t put their own players in conflict. So space is the issue because the defense might have to ask one of the high safeties (usually the weak/boundary safety) to be in the run fit. This ask isn’t always advantageous because he is coming from distance (or in other words, there is more space from him to the ball carrier than there would be from and inside linebacker to the ball carrier).
There are ways the defense can play a gap-sound defense from a two-high structure. While this could be the place to go over those ways, we must move on for the sake of time. I suggest checking out this tweet from Kyle Cogan and its replies and reading this blog post by Barry Hoover for an introduction to those tools.
But for the rest of this post understand that we are approaching RPOs as a tool to fix the numbers problem. It doesn’t matter what structure the defense is in — one-high or two-high — every RPO solves the numbers problem whether that’s reactive to the defense having a numbers advantage in the run box or by the defense having a numbers disadvantage in the passing space.
Post-Snap First Level RPOs
The TE Flat RPO is an example of a post-snap first level RPO (reading defensive ends). This opens up the play to a lot of issues because the defender being read (a defensive end) has no pass responsibility. This RPO is evidence to the point about why RPOs need to be understood in the context of numbers, space, and leverage rather than conflict defenders.
Here is a drawing of one variation of the play:
Who is in conflict? Is the defensive end responsible for covering the TE going into the flat? This play only works when nobody covers the TE. That doesn’t mean it’s a bad play — far from it. It only means that this play is not about putting a defender in conflict. That framework for understanding RPOs falls apart on this play. Understanding numbers, space, and leverage are better tools to work through this play.
Example:
This play doesn’t work because the Mike was not a part of the run fit and instead was responsible for the TE. So even though the defensive end crashed and gave the QB a throw read, the play didn’t work because there was no conflict defender. In other words, the QB didn’t have a proper framework to think through this play and solve the problem the defense gave him.
At the beginning of this post, I mentioned two use cases for RPOs:
RPOs are a tool to prevent the offense from running against a box where the defense has a numbers advantage (accounting for numbers in the box).
RPOs are a tool for the offense to attack defenses who are playing with poor space control (bad leverage) in the passing space even on a run play.
So this TE RPO is an example of the second reason. However, by the nature of how long this play takes to develop, the read is a difficult one for the QB. He can’t read one player and make his decision off that player like he would in the traditional way of reading a “conflict” defender. Looking at the play working will illustrate this point better because you can see that when the play works it’s because the number problem is solved.
Here is an example of the play working:
The motion helps the offense gain the advantage in numbers quickly. And that’s the essence of what makes this play work: overloading a side of the defense to gain a numbers advantage. This gives space in the offense’s favor and leverage gained by the TE on any flat defender (if present) allows the throw to the TE to work. If a defender gains leverage on the TE in the flat, then the QB can run the ball up the field. So this play is a really just the triple option.
The defense should have someone responsible for the dive, the QB, and the pitch (the TE in this case), but if they don’t have sound option principles, then this play works. And like any triple option play, the offense has to have a numbers advantage for it to work.
So a better way to teach this play is to teach it like a triple option play. The QB is to first read the end man on the line of scrimmage for the dive/keep decision. Then he is to read the first outside defender for the keep/pitch read. That makes this play more sound because it gives the QB options to deal with the number problem instead of asking him to read a defender who isn’t in conflict.
Post-Snap Second Level RPOs
Second level RPOs (reading the linebackers) are also about either accounting for numbers in the run box or making the defense pay for not playing the pass well. The conflict defender framework does not work with these types of RPOs.
This one is a little harder to grasp especially after watching the example below because linebackers are constantly bouncing between defending the run or the pass. However, remember the main argument of this post: RPOs are about fixing a numbers issue in the run game or about taking advantage of the defense not covering people in the pass game on run plays.
Here’s the example (source):
The offense is in 12 personnel so they are presenting eight gaps to the defense. Thus the defense needs to figure out how to cover these eight gaps. The Seahawks choose to do that by placing eight defenders in the run box. The 49ers can’t block all eight defenders — thus they have a numbers disadvantage in the run box. QB Jimmy Garoppolo confirms this disadvantage post-snap when he sees the weak linebacker (#56) step up into the run box. However, what makes this play interesting is that it’s an outside run away from the defender the 49ers do not block (#56). So realistically, was that inside linebacker in a position to make the play? Probably not, and definitely not at the point of attack. So is this sound defense? Does that inside linebacker need to fit the run if the run is away from him?
This is where the conversation around “stealing” gaps comes highly relevant in this post. #56 linebacker is aligned in the run box pre-snap so the defense is sound in the box. But he doesn’t need to fit until he gets a confirmed run or pass read. I am not sure what the defensive answer to this play is other than trying to steal gaps with the Mike linebacker and the defensive line. Additionally, the post safety is the inside help for the cornerback covering the slant. However, because the WR is aligned tight, the cornerback has to play with outside leverage due to divider rules. This turns out to be a problem when the weak linebacker steps toward the run. Another reason this play is more about leverage than it is a conflict defender.
Here’s another second level RPO with a WR screen that demonstrates the numbers issue the defense must solve:
This play works because the defense doesn’t cover the WR screen. The offense is in 11 personnel so they are presenting seven gaps to the defense. Thus the defense needs seven defenders to cover every gap or they need some way to steal gaps if they want to defend each gap with less than seven defenders. Iowa chooses to fit with eight by playing in a MOFC structure.
So they wasted one of the defenders in the run fit and because of this misallocation of resources, they do not have anyone left to cover the WR screen. So this play isn’t about putting a player in conflict, but rather unsound defensive play. Iowa doesn’t have a conflict defender in this play — they are mistakenly playing with too many defenders in the run fit. Again, this is a numbers issue for the defense that the offense’s RPO allows for them to take advantage of.
Post-Snap Third Level RPOs
Third level RPOs (reading the safeties or corners) also reveal that RPOs are about solving the numbers problem through space and leverage.
Here’s an example of the best third level RPO team taking advantage of the defense playing unsound defense in the backend (source):
The offense is in 11 personnel, but they are presenting nine gaps to the defense by their formation:
The defense is outnumbered in the run box, but QB Joe Burrow throws the ball so the run box numbers problem isn’t the problem he is fixing. Instead he is taking advantage of the good numbers and good leverage the offense has on the glance route run by the solo receiver. The defense has allocated the weak safety to the run fit, so he can’t also be responsible for covering the solo receiver if the defense hopes to be sound.
So this play takes advantage of the defense abandoning space in the pass game since the cornerback doesn’t have enough help on the inside. Simply put: the QB sees an advantageous one-on-one matchup in the pass game and takes it even though a run play is called.
Why Reading Conflict Defenders is Costly
When the defense plays one-high (MOFC) then they are able to play +1 in the run game. This is the clearest example of the defense having no conflict defenders. If the offense follow the framework that RPOs are about conflict defenders, then they won’t have an answer. If they have no answer, then they will lose the numbers advantage every time.
Example:
The offense is in 11 personnel, thus presenting seven gaps to the defense. The defense is playing MOFC so they have the numbers. Who should the QB read?
Asked another way, how can the QB fix this numbers problem in the run box? This play demonstrates that viewing RPOs as a way to answer the numbers problem is the proper way of viewing RPOs because there is something the QB could’ve done that is built into the play. But he would’ve only been able to see it and execute on it if he had an understanding of defensive structures through the lens of numbers, space, and leverage. I say this without knowing what this Tennessee QB is taught, maybe he is taught to just live with the numbers disadvantage — I would argue this isn’t sound offensive play, however. Instead he could throw one of those hitches and fix the numbers problem that way.
No defender is in conflict but there are still opportunities for the offense to capitalize on the defense’s inability or unwillingness to cover space tightly on this play. The hitch by the number one and number three WR are available because the defense is giving space to them by alignment and post-snap movement. And if the defense was covering down tightly, the offense could check into a fade (like the Shock concept) or any other run-away route concept (like double slants).
Here is another example:
Texas is in 12 personnel so they are presenting eight gaps to the defense and Alabama matches that with eight defenders. So Texas has a numbers problem. They can still use an RPO to fix this problem even though there is no conflict defender. They have routes attacking the defense’s outside leverage called in this passing concept. Alabama is playing with divider leverage so they are trusting the MOFC and sideline to help. So the right answer is the outside slant which is able to win inside. Now that route would’ve worked here because the cornerback spun out to defend a vertical, but the principle remains the same: there was a numbers problem in the run game that the pass option fixed.
A Semi-Conclusion
RPOs are best thought of through the lens of numbers, space, and leverage instead of conflict defenders. In a future post I will dive into how we teach this to our QBs because that is how I stumbled across this issue. Upon researching what others had to say about the topic, I found defensive coaches talking about how to remove their defenders out of conflict and the pieces clicked together.
We’d had issues communicating to our QB how to get through the play when we talked about conflict defenders against MOFC defensive structures. The tools that fixed this problem was by framing RPOs as the solution to a numbers problem first and foremost. After that, it’s all about helping the QB quickly diagnose this problem and then get to the right answer pre-snap and post-snap. For us, this process isn’t refined and we’re working through it every single day. So next week, I will go over how the pre-snap process gives the QB the tools to diagnose the numbers problem.
Until tomorrow,
Emory Wilhite
Resources Used In This Post
Kyle Cogan tweet on “conflict” defenders (read through all the replies for the full conversation/debate): https://x.com/CoachCogan/status/1380324840457052165
Barry Hoover blog post on slinging the fits: https://coachhoover.blogspot.com/2020/03/defending-pistol-spread-rpo-from-2-high.html
Dave Aranda course on slinging the fits: https://coachtube.com/course/football/defending-the-spread-offense-dave-aranda/12383032
- ’s post on Georgia’s Defensive Philosophy:
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