Chip Kelly offense 101: Passing game, part 3

Football is governed by basic arithmetic and geometry. Whether running or passing, the essence of football is arranging a finite number of players on a field in a manner that creates a numeric advantage for your team on a portion of that field.

That’s not an especially new idea — you trace the idea of stretching defenses in the passing game back to Sid Gillman in the 1950s — but it’s an idea that permeates every facet of Chip Kelly’s offense. So far, we’ve looked at how Chip’s passing game stretches the defense from sideline to sideline and how he isolates defenders with high-low reads to try and create those advantages. Next up, we’re adding an additional receiver to the vertical-stretch mix and breaking down Kelly’s favorite three-level stretch concepts.

Saints

Listen to Kelly talk about his offense enough and you'll hear a couple of themes pop up over and over again: 1) put defenders in conflict, and 2) force the defense to defend every inch of the field.

Some of that is coach-speak, sure, not far off from classic training camp lines like, "we want to be aggressive and multiple." But this is coach-speak that Kelly actually follows through with, and it’s not too difficult to see when you pull up the tape. No concept in Kelly’s playbook embodies those basic principles quite like the "Saints" concept.

Saints is Kelly’s take on an Air Raid staple, Y-Cross, and has been a core concept in his passing game going back to his days in Eugene, Oregon.

Kelly detailed the basics of the Saints concept on PhiladelphiaEagles.com:

We have a go route down here on the bottom of the screen, and we have a flat route out of the slot receiver. We’re trying to high-low this side if it stays two-deep. And then our tight end is running the deep drag. [The receiver to the top of the screen] has got a backside post, and then our running back is in the flat.

Let’s unpack that a bit. The first element of the play is actually the outside zone/bubble screen action. We haven’t yet discussed the way Kelly constrains defenses with packaged plays (don’t worry, we’ll get there), but the bubble screen action on the backside of a run play is something the defense gets very used to seeing. This action is important because it pulls the second-level defenders toward the line of scrimmage.

After the run fake, the quarterback turns his attention to the vertical-bubble combination. "If it’s two-deep, we stay on this side," Kelly explains. This creates a high-low read on the cornerback, with the go route behind him and the bubble in front of him. "If for some reason they go to [Cover 3]… what ends up happening on the rotation is that we lose these two players. The quarterback is now working the tight end to the backside post depending on where the free safety is."

With the linebackers held by the run action, and the frontside cornerback and flat defender occupied by the vertical-bubble combo, a void is created in the middle of the field for the tight end’s deep crossing route. Now, as Kelly mentioned, the free safety becomes defender in conflict and the quarterback’s coverage key.

If all has gone according to plan at this point, the free safety is the only defender who can threaten the deep cross, and if he sits in the deep middle it should be an easy completion for the quarterback. But if the safety drives on the deep cross, the quarterback takes the shot deep to the post.

Kelly’s favorite look to run the Saints concept from is the two-by-two alignment (two receivers to each side of the formation) shown in the images above. However, he’ll also run it from one of his standard trips formations, along with the more interesting double stacks look.

Saints is a handful for defenses to digest because there are options against almost every coverage type. The three-level stretch (vertical-deep cross-bubble) is a problem for both two-deep and three-deep zone coverages. The deep cross is also an excellent man beater on its own, but is routinely aided further by the run action. Versus the blitz, both the bubble and the running back in the flat can be thrown hot. And the backside post offers shot-play potential if safeties in three-deep or quarters coverage get too preoccupied with the deep cross.

Boot

Every team in the NFL has the standard naked bootleg concept in their playbook — it felt like it was the only pass on Geep Chryst’s call sheet at points during the 49ers’ 2015 season — and Chip Kelly is no exception. There are a few variants, but the basic formula is always the same: show hard run action to the backside, leak a player into the flat, run a deep vertical or out-breaking route to the frontside, and bring a deep crossing route over the middle.

The final picture downfield for the quarterback is similar to what we saw above from the Saints concept, though how we get there differs slightly, most notably with the flat route. The bubble is replaced with a delayed flat route from the tight end. "Usually our tight end is cutting off this defensive end on this side," Kelly explains, referencing the tight end’s responsibility in the run game. "But now he’s going to let the defensive end slightly beat him, and then pin him, so the quarterback now can get out to the perimeter." At that point, the tight end is free to leak out into the flat.

Once the quarterback is on the perimeter, he wants to get his shoulders square to the line of scrimmage as he moves through his progression so that his body is in position to deliver an accurate ball. Though the frontside vertical/out-breaking route is technically the first read, the ball tends to make its way to the flat or the crossing route from the backside more often than not.

Noise

Run enough of the Saints and boot concepts, both of which feature a deep cross and post on the backside, and eventually defenses will starting leaning inside and overplaying those routes. That’s when Kelly finds the "Noise" concept on his call sheet and uses the defense’s inside leverage against them (I want you guys to know it took everything in me to not write, "That's when Kelly brings the Noise," right here. You're welcome.).

Noise is Kelly’s version of the popular concept you’ll commonly see referred to as "sail," a three-level vertical stretch that attacks the outside third of the defense. While Kelly will run Noise from a more standard drop-back look, he loves to pair it with run action that makes it appear as if he’s running the standard boot concept right after the snap.

We’ll again let Kelly explain the basics:

Our quarterback, with the action, is going to start a roll and it looks like we’re just throwing your traditional naked route, where we’re throwing and trying to bring everyone over to [the right side of the field]. But when we get right near the hash, [the deep crosser is] going to break his route off and then come back out. Tight end is going to go on the backside and protect. And then the running back is gonna be in the flat over here.

Everything starts like your standard boot action — the play fake, the rollout, the blocking, the route stems. But with the deep cross breaking back to the corner and the quarterback pulling up in the pocket, the play turns into a short of throwback pass, where what looked like the backside of the play morphs into the frontside.

The quarterback reads the play like your typical three-level stretch: from deep to short. "He’s reading the safety to start," Kelly says of his quarterback's first coverage key. "If he can throw the ball over the top, he’s gonna try to throw the ball over the top."

If the safety doesn’t bite on the deep cross action from the inside receiver and stays over the top of the post route, the quarterback will move to the corner, who becomes the most frequent target on this play. Finally, "if for some reason there’s some noise or anybody underneath [the corner route], the the running back after the fake is into the flat."

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Combined with a few others we didn’t discuss — notably, NFL staples like the dagger and NCAA route concepts — vertical stretches make up the largest chunk of Kelly’s base passing game. Tomorrow, we’ll round out our look at Kelly’s aerial attack with our final bucket of passing concepts: triangle stretches.