Today, we continue with our “Steelers Playbook” series by featuring a staple of every NFL offense, the Duo play.

Duo is often described as an “attitude play” because it requires everyone on the offense to adopt a physical mindset. It is generally run from an unbalanced set of some sort, whether a compressed bunch, a tight end/wing configuration, or like I’ve drawn in the diagram below, a 3×1 set that motions a receiver down to become part of the blocking surface. The fact that receivers are required to block on Duo means it’s a play that demands total buy-in from the offense to be successful. This isn’t a spread-style concept where receivers are out on the perimeter running bubble screens while the five linemen up front bloody their noses. Everyone has to block on Duo. The greater the buy-in, the more successful the play.

The blocking rules are a combination of gap and zone principles. Everyone up front is blocking down through their backside gap. If there’s a defender in your gap, you block him. This makes the play a bit like Power without the pullers, because of the angles it creates on gap blocks. However, it also incorporates zone principles by having uncovered linemen double-team those first-level defenders to a linebacker. So, everyone up front must communicate where the double teams are occurring and who is coming off onto the backers to make the play successful.

The last blocker to the play-side — usually a wide receiver — is responsible for blocking #2. This means the second defender in from the sideline. It’s usually a safety or a linebacker, so receivers who are willing blockers are necessary. The corner is left unblocked — I’ll get to that in a moment — so that all the box defenders are covered up. In sum, the scheme looks like this:

You’ll notice that the running back has a two-way go on Duo. His aiming point is the B-gap — somewhere between the outside leg of the guard and inside leg of the tackle — and as he presses the B-gap he is reading the play-side linebacker (highlighted in the diagram in blue). If the backer is passive or is being blocked, the back will stay on his track and slam up inside. If the backer presses the gap, the back will bounce the ball wide. This is where he will encounter the unblocked corner. Safeties tend to be better tacklers than corners, so the scheme calls for the widest receiver to cover up the safety and allow the corner to come free. It’s up to the running back to make the corner miss, which is a bet most offenses are willing to take.

As the play-caller in both Tennessee and Atlanta, Duo was an integral part of new offensive coordinator Arthur Smith’s offense. On plays Smith ran more than 50 times with both teams, outside zone had the best yards-per-carry average at 5.4. Duo was next best at 5.1. This is particularly impressive when you consider how Duo is run from heavy, unbalanced formations that often suggest a run is coming. There is no deception to the play — it’s just smash-mouth football. When you’re able to average five yards per carry while essentially announcing your intention to run the ball by how you line up, that’s impressive.

In Pittsburgh, the Duo play should marry well with Smith’s penchant for compressed formations and with the skill set of his backs, particularly Jaylen Warren. In reviewing film of the Steelers running Duo last season, Warren was especially effective. His vision allows him to see seams develop on Duo runs and the suddenness with which he accelerates gets him through those seams quickly. When Warren bounces the Duo play outside, cornerbacks rarely win the one-on-one encounters that ensue. Pittsburgh mainly used Duo as a short-yardage concept the last two years, and averaged just 3.6 yards on 62 Duo runs as a result. Warren, though, broke a couple for big gains, including a 19-yard touchdown run at Seattle in Week 17 last season that was a thing of beauty. If Smith expands the use of the play this season, I’d expect Warren to thrive.

For a video breakdown of that touchdown run and a tutorial on the Duo play, check out my latest installment of the “Steelers Playbook” series by clicking the player below: