Defending the RPO with 3 Safety Personnel

Posted by Alex Kirby on

No play has annoyed and frustrated defensive coordinators more in the past decade than the run-pass option (RPO).

The ability of the offense to seemingly always have an answer no matter what is one thing that a lot of coaches have struggled to find solutions for on the defensive side of the ball.

Jacob Gill is the defensive coordinator at Shiloh Christian School in Arkansas, where the team has had a lot of success on defense, and as a team. 

In this article we're going to be exploring concepts from Coach Gill's presentation on the 3-Safety Defense HERE.

Watch the video below to learn more, or scroll down and read the article.

Defending the RPO from a MOFO Look

First we’ll start by looking at this from a “Middle of the field Open” 7-man coverage concept, what they call "Cover 8".

The challenge is how to defend the RPO, while still dedicating guys to coverage but also having enough guys to play the run.

This look is a perfect example of what makes RPOs so difficult to defend, because not counting the quarterback, the offense has six men in the box (five offensive linemen and the running back). Meanwhile the defense only has five (four down linemen and the Mike linebacker).

Defending the RPO - 3 Safety Defense vs 2x2 - Jacob Gill

The math here isn’t hard, they need one more guy to play the run in the box.

But how do they do that without making themselves too vulnerable to the pass?

It's not as simple as just sending a guy on a blitz, you'll leave extra space open. So what do you do?

Defining Responsibilities

When installing this concept with their kids, they use diagrams with three different colors.

Red tells them they are definitely in the run fit, yellow means they are *possibly* in the run fit (more on that later), and green tells them they are definitely NOT in the run fit.

See the diagram below for an example.

Defending the RPO - Slinging the Fit - Jacob Gill

Slinging the Fit

So what about the guys who may or may not be in the run fit? How is that determined? In this example that would be the Star and the Will. 

It all starts with the offensive backfield, specifically the quarterback. When the ball is snapped, where do his eyes go? 

For example, if the QB looks to the defensive left after the snap, out of this alignment you’re probably getting some kind of downhill run game from the tailback. Since the quarterback is looking in his direction, the Star is the guy who is probably being read in an RPO. 

Defending the RPO - 3 Safety Defense vs 2x2 - Jacob Gill

The specific pass pattern attached to the play isn’t that important, but if the Star sees that action and the quarterback is opening up toward him, he should “sit”, and he’s referred to as the “sit player”. You may have heard this referred to as a “pause player” as well from other defensive coaches when talking about defending the RPO.

At the same time, the Mike knows he’s automatically in the run fit to the frontside of where the quarterback is looking. He’s working inside-out, and reading A to B to C over the top and scraping, and he’s going *right now* since he knows he’s a part of the run fit.

If the “RPO side” is to the defense’s left, or to the side of the Star, that means that the Will is NOT being read. As a result, he’s going to be the guy the defense moves into the box and becomes the sixth run defender they were looking for. 

The Will in this case is referred to as the “Fold” player.

Sit, Fit, Fold

When teaching this technique for defending the RPO, Coach Gill uses the phrase “Sit, Fit, Fold”.

In the example we just talked about, the Star would be the “Sit” player, the Mike would be the “Fit” player, and the Will would be the “Fold” player.

If the RPO is going to the opposite side, then the “Sit” and “Fold” responsibilities are flipped.

Defending the RPO from Trips

In anything they do, Coach Gill is going to start from a 4-2-5 background and philosophy, and try to keep the rules as close as possible whether they are in a 3 high safety defense or a more standard 4-2-5.

Against a trips formation, they’re going to walk out the Mike linebacker to a “50” technique, stacked over the end, and bump over the Will linebacker into the A-gap.

The difference here is now that the Star is removed from the box entirely, he’s going to be removed from the run fit entirely as he’s lined up across from #2 in their pattern match coverage. Now if the offense wants to read the Star as part of the RPO, he’s in pass coverage no matter what, so he should be conflicted by any mesh or play action, and the defense still has the ability to get numbers in the box and play the run.

Here’s how they do it…

Now the Mike and the Weak Safety are the two guys who are “Slinging the Fit” and the Will is the guy now who is automatically in the run fit.

See the diagram below for the specific responsibilities.

Defending the RPO - 3 Safety Defense vs Trips - Jacob Gill

Out of this look, with the running back to the trips side, one of the most common RPOs is the back going away on the mesh, reading the defender closest to #3, and throwing the stick or hitch route to the uncovered guy. For example, if the Mike chases the run, the QB throws the uncovered route, and if he sits in place to take away the pass, the QB hands off the ball on the run play. 

The advantage for the offense is in theory they get six players on five (five o-linemen and the ball carrier), but that’s BEFORE accounting for the safety coming down into the box and “slinging the fit” as he does here in the diagram.

Now that Weak Safety is playing the “Fold” rules, so as soon as the quarterback opens away from him, he’s coming down to add himself to the run fit and “Fold” into the open gap.

The Mike “Sits” giving the defense a 4-over-3 to the RPO side, taking away the offensive numbers advantage. This also gives them a sixth defender in the box against the run. This is one of the advantages of the 3 safety defense.

The downside? It leaves the corner to the single receiver side one-on-one in pass coverage. 

Coach Gill feels this is acceptable risk, believing that the QB should not have enough time to read the coverage, read the Mike, decide if he’s going to hand the ball off or not, then turn around and flip his hips, and come back and find the backside receiver.

The way this likely plays out, is that the quarterback hands off the ball into a six-man box, or if he does throw it, it’s going to be to the Trips side where the defense has a numbers advantage also.

Obviously there is no perfect defense, but this gives them the best chance to put their players in positions to be successful against the RPO.

Middle of the Field Closed (MOFC) Answers

Slinging the fit is usually something that only comes into play when you’re trying to play a 2-high look. This is because you’re naturally a man short in the box most of the time before the ball is snapped, so you need a way to get there against the run and RPO.

When you’re playing a one-high or MOFC coverage, this isn’t an issue, since that extra man in the box allows you to define the run fits for your players a lot more clearly, and there is a lot less ambiguity about who is responsible for what.

Coach Gill prefers to play a 2-high look as often as possible, so they have to be proficient at “Slinging the Fit” and adapting their responsibilities on the run. 

For more information on their MOFC "Dime" package, check out this article.


Coach Gill and the defensive staff at Shiloh Christian are big believers in the 3-safety defense, but they’ve always started their installation from 4-2-5 principles.

If you’re playing a 3-safety defense, you can take these same principles and apply them to what you’re doing out of that structure.

Want more?

Coach Gill has put together a fantastic presentation on the 3-safety defense, which you can find HERE.