Trend Line: 3 Key Adjustments Turning Duo Run Schemes into an Explosive Play Generator

Jun 3, 2025 | Duo Run Concepts, The LAB, Offense, Run Game

Emerging Trend: “Embracing the Bounce by Elongating the Surface”

By Mike Kuchar
Co-Founder
X&O Labs
@mikekkuchar

Everything you know about Duo runs is wrong. Our latest analysis of 3,704 plays from 134 college programs has shattered the conventional wisdom that Duo is merely a “wear them down” scheme.

Our research has discovered that when backs redirect through the C gap, Duo averages an astounding 13.8 yards per carry—more than triple its traditional output. Our latest findings have identified three specific blocking trends that college programs are using to unlock this explosive potential, fundamentally challenging decades of gap scheme philosophy. These aren’t minor adjustments; they’re systematic changes that transform Duo from what Minnesota Duluth’s offensive line coach calls “a bucket of blood” into one of football’s most explosive plays.

Our Key Findings:

Dominant on 1st Down: 46.3% of duo explosives occur on 1st down, with another 37.0% on 2nd down
1st &10 is the sweet spot: A remarkable 44.8% of all duo explosives happen specifically on 1st &10
Best field position to Utilize: Between opponents’ 40-20 yard line

The assumption is that Duo runs generates far fewer explosive plays than other concepts like wide zone. The fact is, Duo runs are traditionally designed for consistency over explosiveness. It’s known as a “wear down” scheme, evidenced by Minnesota Duluth offensive line coach terming the concept, “a bucket of blood.” But when it does produce explosives, we found that when the point of attack changes in the Duo play, it averages over 13 yards a play, with the C gap (13.8 yards) and the D gap (13.5 yards) being the main point of entry.

Primary Key Insight: The common denominator in efficiency lies in allocating more hats to the concept’s backside (which becomes the front side). Duo’s beauty lies in its flexibility. Unlike traditional gap schemes, your back can press, bend, and bounce. The data shows that when backs are forced to redirect, they are often finding the explosive crease. So, we need to train your backs to be patient and trust their reads.

And these are the three trends in how the most successful programs are doing just that.

Trend 1: Bunch and Compressed Formation Duo Concepts

Why Use It:

It forces the corner to be the free hitter
It allows for a bigger surface to the backside (often known as the frontside) of the play.

Why it Works:

This became an easier answer to get 3-4 additional blockers into the boundary for Duo runs in 12 personnel groupings. The rules were simple:

Attached (on the ball tight end)- block the defensive end
Second TE- block the Sam LB
Big Receiver (Z)- block support- typically safety, leaving the corner unblocked

For the last two seasons, Bunch Duo has been the most effective tool for South Dakota State and others who are structuring their Duo play. It’s usually built by motioning in a big slot or Z receiver to fold block the support defender backside. It helps secure those explosives when the ball hits where it should- backside. Essentially, receivers are taught to block the “most dangerous” just as they would in other run schemes.

“Everybody loves when Duo hits for 8 yards up the A gap, but we’ve had many more explosives on sprays when backers plug downhill and we get lateral push and they get trapped,” said Northwestern assistant offensive line coach Ryan Olson. “That’s why we love the play out of Trio or a tight bunch when we fold the receiver in. If we can get that ball sprayed, the unblocked defender is the corner who is the worst tackler on the field.”

In these bunch or compressed formations, the ball carrier understands there is going to be a built-in fold block by the point receiver and the Z receiver. Both receivers talk to each other to communicate who is blocking the overhang defender and who is blocking the safety.

How it Works:

The communication is built off the leverage of the field overhang (or Nickel) defender. From a base standpoint, if the Nickel is head up to outside the point receiver in bunch, it enacts the fold block between the Z and slot receiver.

If the Nickel is inside the point receiver, the point receiver will block him while the Z sorts out the most dangerous defender.

For more on South Dakota State’s Bunch Duo concept, click below:

https://www.xandolabs.com/the-lab/offense/run-game/gap-run-concepts/four-ways-to-get-the-spray-in-the-duo-play/

Trend 2: Building Insert or Tracer Elements into the Backside of Duo

Why Use It:

Makes it difficult for man coverage structures to chase an insert and fit the run
Post-snap split flow presentations often cause second level defenders to misfit the concept
It allows for a bigger surface to the backside (often known as the frontside) of the play.

Another trend we found to get additional blockers to the boundary are these “tracer” or “inserter” elements that coaches were using. The blocking rules are the same as above but now the Z comes from opposite the formation to handle the support defender. It was a great answer against man coverage because it became more difficult for defenders to run with motion and then fit the run game.

Inserter Rules and Technique:

Like most coaches, New Hampshire offensive line coach Brian Scott teaches the backside as the play side in Duo runs because chances are that is where the ball is going to end up. It’s a gap scheme mentality at New Hampshire, where the play is built off massive double teams on the backside. And bringing these tracer elements across to insert on the backside (albeit play side) helped protect the play from defenders who would either “plus” their leverage or bring defenders across the formation. “Teams have started bringing the corner or safety across with him, but that is a long way to go to make the play,” he said. “And oftentimes our back is better than that corner or safety.”

In New Hampshire, the insert tracer can be either a fullback, tight end, slot, or receiver, so the rules for this player have to be general. Essentially, he is taught to find space and block the first color. Who he is inserting for depends on whether or not the staff chooses to combo the C gap defender or block out on the D gap and insert into the C gap. “I prefer to set the edge and insert the H back inside of it,” said Coach Scott. “We will do it differently week to week based on who the 9-technique is and the matchup that we want.”

According to Coach Scott, the insert technique cannot be overcoached because oftentimes he is coming off a motion. “It’s difficult with all these motions to tell him he has a defender,” he said. “We would rather talk to him about color off the edge. We talk about the first color more than anything else. Play everything inside and out on the inside number of defenders but he must stay tight off the tight end or wing.”

Below are the following tags that New Hampshire will add to the Duo play, which will alert which offensive player will be the inserter and where he is fitting.

Base Tag:

This is the most common insert concept in which New Hampshire will run the play. Against any 9-technique edge defender to the nub side, the tight end will block out and the receiver (or H back) will insert inside to block the C gap defender. “We are trying to get him squared-shouldered downhill against a 9-technique and come to balance so that he can see the defender,” said Coach Scott. According to Coach Scott, the main coaching point is to identify color pre-snap and clean up anything that shows. The benefit of this tag is that often it pits the running back on a corner, a lesser tackler.

“Slice” Tag:

The slice tag now tells the Y/H or receiver to cut off the D gap defender. This allows the play side tight end and tackle to stay on the combination on the C gap defender. “We want to make corners make tackles, so we prefer not to block him,” said Coach Scott. It’s been a good adjustment against defensive movement to the three-surface or four-surface side because it allows the offensive line to gap everything down. And if it’s run to the nub side, the unblocked defender is the corner, which is a win for the offense.

This slice tag can be coupled with fly motion, bringing the H/Y back, which is the popular way in which New Hampshire ran Duo last season. It’s done out of heavier personnel looks.

At Waynesburg University last fall, offensive coordinator Greg Luvara even built in double tracer elements to add to the backside of Duo. The rules stayed the same. The first tracer (usually a Y) blocked the Sam, while the second tracer (an H or a big Z) blocked support.

For more on New Hampshire’s Tracer Elements in its Duo concept, click below:

https://www.xandolabs.com/the-lab/offense/run-game/gap-run-concepts/building-tracer-inserts-into-duo-runs/

Trend 3: Using Backside Tackle As Additional Blocker

Why Use It:

Advantageous for an athletic Tackle that can pull and insert into back side of the concept.
Eliminates an added blocker to the front side of the concept that would be rendered useless against Odd front structures

With all the Odd front structures infiltrating the CAA conference, William and Mary offensive coordinator Mario Acitelli tweaked his Duo concept by allowing his backside Tackle to pull and be part of the action play side. “When you run Duo to a three-man front with no weak overhang, the Tackle does nothing and fans to no one,” he said. “So, we decided we would pull him for the high safety and block everyone else the same.”

The Tackle is tasked to pull to the play side to handle the extra support defender. It became an immediate answer for weak-side pressure. “You can search the flanker to handle that, but it limits you formationally,” Coach Acitellii said. “If the weak safety blitzes you are pulling off the end, but the safety would be sitting there.”

So, when the backside Guard is uncovered- as he would be in Odd looks- he simply blocks the C gap defender, clearing the Tackle to pull.

Against Even looks, the D-gap defender essentially becomes the read for the quarterback.

How it Works:

The three-surface Duo concept allows the play side to simply gap down at the point of attack. The play side Tackle and tight end are in a vertical combination to the plus-one LB.