Sizing up Arik Armstead as a Leo in 49ers' new 4-3 scheme

It’s not confirmed where Arik Armstead is playing most of his downs in 2017 in the team’s new 4-3 front, but the 49ers defensive lineman and 2015 first-rounder did lose “15-20 pounds” this offseason, according to teammate DeForest Buckner, and Leo is where he’s been lining up since minicamp.

This would mean a high-priced 4-technique in Year 3 would be kicking outside to become an out-in-space EDGE and primary pass rusher for the 49ers.

Square peg, round hole, right? Because of that, this is a storyline that is generating all kinds of talk.

As a valued 6-foot-7, near-300-pound interior DL hailing from Oregon’s 3-4, defensive end on the open side of a 4-3 formation is not quite where most projected Armstead to ever play during his NFL career. At first glance, it doesn’t appear to be his most natural fit, especially since Leos are often the smallest and quickest of that group of linemen.

Coaches Dan Quinn, Pete Carroll and Gus Bradley are all authorities on the position, and new 49ers defensive coordinator Robert Saleh worked under them all. Here’s how Quinn, ex-Seahawks defensive coordinator and current head coach of the Falcons, described the requisites of the Leo position, via the MMQB:

“Initial speed. You have to be able to beat someone off the ball who is going to be stronger than you. Then you have to be able to use the length—length is important—and have the relentlessness to finish.

“Then with the mental makeup, with both cornerbacks and rushers, you have to be a relentless fighter. There’s a 330-pound bear in front of you, and you just have to figure out a way to beat him. You have to be fast enough to run with the running backs and tight ends and strong enough to fight a bear. You have to be a unique dude.”

Carroll, who mentored Quinn in Seattle, and originally conceptualized what this defense is today—which is loosely based on the mid-90’s 49ers with the Leo-driven defense being an offshoot of the “Elephant” set—also went into detail about what is expected of the position (via Field Gulls):

"The best pass rusher on the team is usually the defensive end to the open side of the field.

“That puts him on the quarterback's blind side and makes him a C-gap player in this defense. We often align him wider than this in order to give him a better angle of attack and allow him to play in space. We align him a yard outside of the offensive tackle most of the time. He has to play C gap run support but at the same time he is rushing the passer like it is third and ten. He has to be able to close down however if the tackle blocks down on him.

"He has to be one of your best football players. Size does not matter as much. We want an athletic player who can move around."

Given this quick history lesson on the Leo position, let’s look at where Armstead may struggle to transition and where he may have an edge.

Armstead’s Biggest Challenges

Armstead’s strengths do not lie within his speed or flexibility. He is not the type of a player to win with his get-off or by going low and sweeping underneath offensive tackles. A lot of backside rushers, especially Leo types, win that way. Armstead is more head-on power and length.

Below is a visual representation of where Armstead would theoretically line up as a Leo, as shown by Big Cat Country (SB Nation’s Jaguars blog, a team which still runs that defense, and is where current 49ers defensive coordinator Robert Saleh made a stop after Seattle). The Leo here is No. 91 on the Seahawks, Chris Clemons. Here he is lined up in both base 4-3 fronts, the Over and the Under.

There is also a Bear Front where the Leo stands up, which you can read more about here.


Operating with this kind of space, it’s clear to see why speed and a low center of gravity helps.

And, oddly enough, on this particular defensive line, being a power-first player is the makeup for every other position except the Leo. Either as a two-gapping lineman or holding it down as the 3-tech, those three base positions see their best results from bigger, stronger players—ones like Armstead, frankly. Ultimately, the third-year lineman will be going against the grain from a prototype standpoint.

And the biggest hang-up is that going from a phone booth to out in space, Armstead’s greatest asset, his size, becomes less valuable. Out on that island, it becomes more about burst, quickness and athleticism. Knowing that, let’s see how he measures up against recent Leo prototypes from an athletic angle.

Using Falcons' Vic Beasley and Broncos' Von Miller as controls for the measurables, we can see Armstead does not resemble a traditional Leo:

Based on the jump and short-area quickness metrics recorded at the NFL combine, there is evidently a lot more explosiveness, balance and agility from Beasley and Miller, which is the package that enables them to excel on the edge. They were both leaders in nearly all of these categories in their respective draft classes.

If there’s a concern, it’s that Armstead won’t have the pure quickness and bend to challenge offensive tackles. It’ll be Armstead’s strengths vs. the lineman’s strengths, which is power vs. power for the most part. There is no advantage like the ones that Beasley or Miller possess as hair-on-fire book end pass rushers.

And since Armstead won’t be right in front of the quarterback anymore, it may hurt to not have speed and agility as tools.

Armstead’s Advantages as a Leo

While he doesn’t possess the initial quickness Dan Quinn looks for in his Leos, Armstead has been successful in the NFL mostly due to length, which was identified as another important quality by the coach.

Armstead brings 33-inch arms to the table, which may be his biggest asset. If you look at a handful of other recent prospects, they’re about on par for a Leo. Beasley of the Falcons has 32 ½ inch arms, Dante Fowler of the Jaguars has 33 ¾ inch arms, and Bruce Irvin, drafted as a potential Leo in Seattle, has 33 3/8 inch arms. If Armstead keys in on using his length in 1-on-1 matchups, he may see some wins outside.

The 49ers defensive lineman has also already experienced NFL success from a pass-rush perspective.

Armstead in 2016 led all 3-4 defensive ends in Pass Rush Productivity, according to Pro Football Focus. He had 21 hurries and three sacks in 168 pass-rush snaps. This was a year after his rookie campaign when he finished with an NFL-best PRP rating for 3-4 ends (38 total pressures in 236 pass rush snaps). While he’s been doing this from a different technique, the numbers do show a defensive player winning his matchups.

Armstead most notably has been second in Pass Rush Productivity for 3-4 defensive ends since he entered the league in 2015, ranking him second in the NFL only behind three-time Defensive Player of the Year J.J. Watt.

The ability to finish was also highlighted by Quinn, while Carroll said the Leo has to be one of the team’s “best football players,” and “an athletic player who can move around." A high draft pick with production to date, and one that’s played across the defensive line, Armstead certainly fits that description. And while he’s not Beasley or Fowler athletic, Armstead was a dual-sport athlete.

Armstead was a D-I basketball player for the University of Oregon, and even more involved in the game as a high school player in his home state of California.

Coming out of Elk Grove, Armstead was a two-star recruit as a power forward, according to’s rankings. It was there that he was a three-year high school starter, averaging a double-double by his senior year, when he was listed at No. 3 in’s Top 40 boys basketball rankings for the class of 2012. Armstead appeared in one game for the Ducks as a red-shirt freshman before committing to football full-time.

In addition to his length, pass rush history and moderate athleticism, he can offer two more key features as a Leo.

The first is that it can become incredibly difficult for teams to call outside runs to the weak side with Armstead out there. He’s built like an NBA player. And with his sheer size and massive wingspan, and often only partly shaded by the LT and with no blocking tight end most of the time, running backs are going to have a tough time getting to that edge. He can own that area.

The second is that Armstead can collapse the pocket from the outside and cause quarterback movement. With his productivity thus far, he is still going to find ways to cause disruption in the pocket, and ultimately affect plays. Even if he can only come downhill, and struggles to turn inside toward the passer like some fear, the quarterback is going to feel that pressure. He’s going to sense his blindside protector getting knocked back.

What to expect

New defensive line coach Jeff Zgonina has talked about a healthy rotation along the defensive line, and there’s also been word of multiple defensive linemen playing different techniques depending on the situation. Armstead is likely one of the players to fall into both of those categories, so don’t expect him to be pigeonholed at Leo, even if he “wins” the starting role in camp.

But, when Armstead does line up as a Leo, how will he do?

It looks like the case shows his game could spike in one direction or another, or it can blend together to make for average results. So, really, anything can happen. But he might not be as out of place and unproductive as many have projected for Armstead to be in that role.

Overall, at 23 years old, he is a young, above average defensive lineman on the right trajectory.

Media courtesy Big Cat Country, Pro Football Focus,, OregonLive

#sanfrancisco49ers #49ers #arikarmstead #leo #nfl #jeffzgonina


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