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Notes: Mini-film breakdown of Swift’s 54-yard run

Is it zone or duo?

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NFL: OCT 18 Lions at Jaguars Photo by David Rosenblum/Icon Sportswire via Getty Images

Earlier this week, The Athletic’s Nick Baumgardner posted some nice praise for 73 LG Jonah Jackson and 72 RG Halapoulivaati Vaitai on the long run by 32 HB D’Andre Swift in the first quarter against Jacksonville:

At first, I hadn’t looked at the play much, and the description by Baumgardner looks about right at face value. But then I noticed a reply from Chris Burke, which seemed really odd. According to Burke, Frank Ragnow made a point of praising the play design but split zone is a relatively ordinary stock/standard play. That seemed like a very strange thing for Ragnow to throw into the comment.

So for anyone who is not familiar with the “Inside Zone vs. Duo” running joke on football film twitter, it is essentially this: someone posts a clip of a run play and asks if the play call is an inside zone run or what’s called a “duo” play. Then replies flow in on both sides arguing zone or arguing duo because a lot of the superficial parts of the play look very similar. This led former Lions offensive lineman Geoff Schwartz to actually write an extended explainer article and put together a video to lay out the differences between IZ and Duo: footwork, play flow, double team assignments, etc.

If you have never heard of “duo,” here is Jim McNally explaining the play:

What you need to know is this: Duo is a gap blocked power play with double-teams at the point of attack and no pulling lineman. It often looks like a zone play because the blocking on zone usually has a combo block from which one lineman peels to the second level. There is a very clear difference on what the two types of plays are trying to do, though, because a gap blocked play has a designated hole the runner is supposed to hit. Zone plays involve all of the blockers flowing and the back finding the tear in the defense: there is no set hole to attack, only a general indication of “inside” or “outside.”

Now, let’s come back to the Swift run. Here’s what is going on:

Week 6 at JAX, 1Q (1:51). First-and-10 at the Detroit 25.

The Lions offense has two tight ends on the field, and the Jaguars counter by sending a heavy personnel package on defense. Additionally, the offense is lined up tight with both wide receivers standing with a 2-yard split from the tight ends. This brings the entire defense in close: 29 S Josh Jones drops down to give the Jaguars an 8-man box with five defensive linemen on the field. The corners are backed off (23 CB C.J. Henderson is off screen to the right above 11 WR Marvin Jones), and there is a single deep safety. This is Cover 1 all the way, with 47 LB Joe Schobert on 88 TE T.J. Hockenson and 29 S Josh Jones picking up 83 TE Jesse James.

At the snap, James goes backside as if he’s making a slice block on a split zone play, and he gets the unaccounted for end man on the line of scrimmage 55 DE Lerentee McCray. It’s not Y-Motion because he’s stationary at the snap, but it’s a kind of halfway deal, almost like a super long trap block. Hall and Hockenson run routes, carrying away Schobert and the deep left corner. From the TV broadcast angle, we can see why Swift had nobody to beat: the box safety Jones follows James across the formation (that’s his man coverage assignment) and the cornerback follows Marvin Jones across the defensive side of the tackle box (that’s Henderson’s man coverage assignment). With both secondary players running themselves across the formation away from Swift’s run path, there’s simply nobody home when he hits the second level.

This is pretty weird! Why would Marvin Jones go that way and why would Ragnow not release up to attack the safety coming across into his lane on zone? Because it’s not zone. Here’s Geoff Schwartz’s flowchart:

Is it zone or duo? Well, is it a run to the tight end side? Technically, yes because Hockenson releases into a route so the side of the formation where the blocking TE started is the right side. Does Ragnow work frontside? The answer is no, he does not. He never takes the bucket step to flow with the play to the right; he immediately goes backside to double Costin with Jackson. Does Decker on the backside block the defensive end? Yes, he reach blocks big on big against Gotsis. So at least by the flowchart, we would suspect duo rather than zone.

What about all the weirdness with Marvin Jones and the two defensive backs? The last part of Schwartz’s video helps explain that piece of the play. The defense brings a safety down into the box, and he becomes the wide receiver’s responsibility. So the defensive call forces Josh Jones to follow Jesse James, and then Marvin Jones’ assignment on the offensive call forces him to follow Josh Jones. Finally, C.J. Henderson’s defensive assignment forces him to follow Marvin Jones; everybody is chasing someone across the formation to the backside and it all works out splendidly for Swift.

One last reason to think this might be duo is what happens right before the snap. It looks like Ragnow could be pointing at Josh Jones, marking him as the Mike. In duo, according to both Geoff Schwartz and Jim McNally, the center is not going to work to the Mike on duo. Instead, he doubles immediately and works backwards to the Will if there is an opportunity to come off to the second level. If you watch the angle that Nick Baumgardner posted in his tweet, you can see Ragnow immediately engages a double backside and his head comes around tracking 44 LB Myles Jack, who should be considered the Will if Josh Jones is the designated Mike.

So is it zone or duo? Probably duo, and a really funky duo play at that because it has no frontside edge double team block and a TE slice block sealing the backside. If this is the call (or at least something close to it), I would heartily agree with KNARFWONGAR that it is a pretty cool play design. Regardless of the play design I would also agree with Baumgardner that the play was very well blocked by the entire offensive line.

Now, on to the rest of today’s Notes:

  • The Detroit Lions are middle of the pack (16th widest) when it comes to how spread out or tight their offensive formations are:

“It was really just a Detroit thing,” Nelson said via Zoom on Thursday. “They reached out to me in the predraft process and were like: ‘Hey, we don’t really see you as a defensive lineman. Would you mind switching over to the offensive line?’ And kind of went over like the barebones plan of, ‘OK, you’re going to come in, essentially redshirt you. We don’t see you playing at all the first year. We’re going to put some weight on you. You’re going to learn how to play offensive line,’ and essentially go from there.

  • From Justin Rogers at the Detroit News, the Lions have a new offensive assistant coach, and he’s extreme:

  • From The Athletic’s Chris Burke, one hypothetical trade that Sheil Kapadia (also with The Athletic) thinks could happen is the Lions trading a linebacker who has become a role-playing blitzer to a team that likes to do that:

Given Ryan Shazier’s retirement last month and Devin Bush to injured reserve this week, it’s not a far-fetched idea.