Duo is a great running play.
It’s versatile, so it can be run effectively out of different personnel packages and formations, and it works against a variety of fronts. It can also be used for different purposes from the offense’s perspective. Want to knock the defense off the ball and play a more physical brand of football? Call Duo. Want to provide a change of pace from your zone-running schemes? Call Duo. Want an answer for aggressive linebackers and blitzes inside? Better call Duo.
So what is Duo? It’s a gap-scheme run (down blocks to the play-side) without pullers like you have on power and counter. It generally gets multiple double-teams, although the number of doubles will vary based on the formation and defensive front.
Below, you can see how the 49ers ran it with success against the Steelers during Week 1 of the 2023 season: