“Power” with a fullback kicking out the end and a backside guard pulling to the frontside linebacker is a play that epitomizes physicality. It was a tone-setter for offenses but it’s not a concept that’s called a lot in the NFL anymore. Professional teams have transitioned to more zone blocking and the fullback was a dying breed — they’ve recently made a bit of a comeback but they’re mostly used in outside zone systems. The Patriots run some 1-back power and the Ravens run QB power option (inverted veer) but traditional 2-back power is more of a short-yardage or changeup call rather than a base play now.
Stanford running 2-back power:
Instead, teams use “duo”, which is often described as power without a puller. It’s a gap scheme play with man blocking upfront but the ball carrier will read it with zone principles. It can be hard to tell apart from inside zone but the main difference is the type of double teams used. With inside zone, blockers are moving laterally on their combos from defensive tackles to linebackers. With duo, blockers focus on getting vertical with their double teams — they step forward, toward each other and try to displace defensive linemen vertically to a second-level defender.
Another big difference from inside zone is that the center works toward the backside linebacker (will) and the frontside combo works toward the designated mike linebacker, which isn’t always the middle linebacker. In the diagram above the sam linebacker (S) is designated the mike, so the frontside combo works to him.
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The running back’s aiming point is the outside leg of the play side guard and he reads the movement of the mike to make a decision where to go. The play can go anywhere depending on his read. His job is to “play cat-and-mouse with the mike” as The Athletic’s Nate Tice would say. After he makes a decision based on the mike’s movement, he’ll look for other visual cues to decide where to run.
If the mike “hangs” or stays inside, the running back could bounce the play outside.
If the mike plays fast to the outside gap, the running back stays on his vertical track.
If the mike and will play fast to the play side, there’s potential for a cutback.
A running back has to really understand the blocking scheme well and have good vision to run the play effectively. The Titans Derek Henry is one of the best duo runners in the league and he scored two touchdowns running it in Week 17 against the Texans.
Week 17, 15:00 remaining in the second quarter, second-and-2
The backside blockers’ fan block, meaning they’re blocking the man in the gap away from the play side. The center can work to the will linebacker right away but he can also combo block with the play side guard if there is a defensive tackle in the play side A-gap. He can make a “me” call or “you” call to communicate to the guard what he will do.
In the image above, there was a defensive tackle in a 2i (inside shade of the guard) but the center went directly to the will linebacker, so the guard had to block the defensive tackle on his own. The right tackle and right guard had the frontside double team, so they had to block the defensive linemen in between them vertically to the mike. The tight end blocked the edge player. Duo is a strongside run play, so it’s always called to the tight end side.
Henry saw the mike “hang” inside so he bounced the play outside.
Henry didn’t go all the way outside because the tight end kicked the edge player out. He used his vision and ran through the D-gap. Once he got to the second level, he made the Houston defensive backs look like children as he ran through several tackles for a 52-yard touchdown.
There he goes! 🤩 @KingHenry_2
📺: Watch #TENvsHOU on CBS pic.twitter.com/3veLRwpkcL
— Tennessee Titans (@Titans) January 3, 2021
Week 17, 9:59 remaining in the third quarter, second-and-1
Later in the game, Titans offensive coordinator Arthur Smith called duo again on second-and-short. He ran it toward a bunch formation, which is how the run is usually called.
Again, the Texans had a defensive tackle in the frontside A-gap. This time, the center doubled the defensive tackle to the will instead of going straight for the will. On the backside, the right guard and tackle fan blocked the defensive linemen on the backside.
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The two tight ends in the bunch had the frontside combo on the outside linebacker (No. 57) to the mike (No. 41). The cornerback (No. 26) was left unblocked by design. If the offense doesn’t have enough blockers, they’ll usually leave the corner — usually the worst tackler on the defense — unblocked and force him to make a tackle.
The center and right guard obliterated the defensive tackle yet the guard was still able to regain his balance to get a piece of the will. The two tight end combo got movement on the outside linebacker (No. 57) but couldn’t get to the mike (No. 41).
But the mike hung inside for too long again, so Henry bounced the play outside. The unblocked corner went too far inside because of Henry’s initial vertical path and he couldn’t make it outside to tackle Henry. Maybe he didn’t want to — tackling Henry probably isn’t fun for a cornerback.
Another Derrick Henry TD 👑 @KingHenry_2 #Titans
📺: #TENvsHOU on CBS
📱: NFL app // Yahoo Sports app: https://t.co/fohj8JnptQ pic.twitter.com/9O28fTiDJb— NFL (@NFL) January 3, 2021
Duo is usually run from compressed formations with multiple players attached to the line of scrimmage but some teams are running it from spread formations as well. I believe it’s an effective play because it’s a gap scheme concept that allows blockers to fire off the ball and execute physical double teams, while the threat of the ball being able to attack anywhere on the line of scrimmage keeps linebackers subdued for a second.
Ted Nguyen is a NFL staff writer for The Athletic. He breaks down film to uncover the story that the X's and O's tell. He also covers the latest trends around the league and covers the draft. Follow Ted on Twitter @FB_FilmAnalysis
