49ers Film Room: How Shanahan exploited Seattle's defensive coverage rules
Kyle Shanahan dug deep into his bag of tricks in a week 15 21-13 win over Seattle to take the NFC West division title.
The 49ers have won seven straight since losing to the chiefs in week seven at home. Their latest victim: the Seahawks on the road in Seattle. The culprit: Shanahan’s passing concepts that took advantage of Seattle’s coverage rules and responsibilities. The 49ers won 21-13 in a game that didn’t really feel that close. The Seahawks added a late touchdown but were largely ineffective on offense all game long.
That meant that the Seattle defense had to play nearly perfect and they didn’t even come close to a good game due to three coverage busts that led to two touchdowns. On the third one, they were lucky that San Francisco didn’t come away with any points and that sort of gave them hope. But the 49ers defense came through like it always does.
On the night, Brock Purdy was 17-for-26, 217 passing yards, and two touchdowns. The run game stats look good on paper, 34 carries for 170 yards, and 5 yards per carry. But two of their runs went for 78 total yards. Take away those two carries and those yards, and the yards per carry falls to 2.88. Seattle just plays the run well but the 49ers were able to get some yards after Seahawks defensive tackle Bryan Mone went down with an injury. They were already without Al Woods.
But the passing game was able to carry the slack in this one with two big touchdown passes to George Kittle. And Shanahan did it by simply using Seattle’s own rules against them.
First play, 1st quarter, 2nd-and-8 @ SEA 28, 3:56 remaining
Shanahan dove into his bag of tricks on this one. This is a play the 49ers have not run since 2018 when they called it versus the Rams in week 17, part of the package of plays that got George Kittle to the single season receiving record for tight ends. It is a fake double swing pass Y delay concept, and it’s a concept Bill Walsh made famous.
The first time we saw this run was in 2018 versus the Rams in week 17 to get Kittle closer to the record. Rumor has it the play call has “Hollywood” in it for the acting job that Kittle does to sell the play.
On the play call, you can see Kittle fall down while simulating a block on the defensive end. This gets the defense to flow with the fake swing pass to the right (after the fake swing to the left holds the defense on that side) and as soon as they flow, he gets up, runs down the seam, and catches the pass.
On Thursday night versus Seattle, the 49ers ran the play out of regular shotgun instead of pistol but the motion is still essentially the same. Kittle doesn’t fall on this one, he chips the defender to sell the swing pass action with the pulling lineman to the right.
The Seahawks are in a nickel cover-9 defense (cover-3 with safety rotation away from the nickel defender) with Coby Bryant (No. 8) responsible for Kittle in the seam-flat area.
Shanahan knows that moving Christian McCaffrey all over the field messes with the defense post snap and gets them to clue in on him and this is sold by the fact that the Shanahan tagged a puller in the play call with right guard Spencer Burford pulling out to the edge to lead block for McCaffrey. This gets the defense to bite hard, including Bryant. Bryant loses Kittle after the flow toward McCaffrey’s swing.
On the other side, the first fake swing pass pulls the defense down toward that route, including the buzz safety. Kittle gets open over the middle and takes it to the house for the game’s first touchdown. Safety Quandre Diggs (No. 6) was shaded too far over away from the post zone to prevent any touchdown.
***12/24 UPDATE***
It has been brought to my attention by Allan Basso of the Twitter account at-Endzone51 that 2018 was in fact not the last time the 49ers ran the double fake screen Y delay before this past week in Seattle. They threw it in week 18 versus the Rams in a win that clinched a playoff spot for the 49ers.
And here’s Kittle explaining the play this past Monday night during the week 15 Rams at Packers Monday Night Football Game:
Thank you Allan!
Second play, 3rd quarter, 2nd-and-5 at SF 46, 14:12 remaining
This is a play call the 49ers have called with regularity since Purdy took over, calling it 5 times alone versus the Dolphins and and three times in a row in that same game. Purdy was never quite able to get to the corner route until now.
The 49ers 4x1 snag concept is run to the 4-strong side with a swing route by the running back, a corner route, a snag “over the ball” route, and a backside slant route if the quarterback likes the match-up 1-on-1 and sees bump or press coverage. The swing route also has a lead blocker arc to the edge in case that pass is thrown.
On defense, the Seahawks are in their base 3-4 front playing a cover-3 drop-8 coverage from a 6-2 front. In their system, the corner would have a “smash” rule for zoning off if the #1 receiver is under. This is to prevent the offense from completing an easy corner route versus cover-3 coverage.
Corner Tariq Woolen should zone off here when Jauan Jennings runs the snag route over the ball. Instead, he chases him over the middle and with the underneath coverage following McCaffrey out of the backfield, it leaves Kittle wide open alone on the corner route.
Purdy checks the backside slant first before moving through the progressions and finding Kittle as the last read in the progression thanks in part to the pass protection for holding up. Aided by poor tackling, Kittle rumbles to his second touchdown of the game.
Third play, 4th quarter, 2nd-and-6 @ SF 43, 7:28 remaining
For defenses that base out of cover-3, they primarily do not want their corners playing as a force defender versus the run. The Seahawks scheme over the last decade-plus has challenged that conventional wisdom, especially in the legion of boom days, by playing with corners who were bigger, faster, and stronger than most NFL corners and ones who could tackle really well too.
Richard Sherman, Brandon Browner, and Byron Maxwell were just a few names who could play deep downfield as well as mix it up around the line of scrimmage versus opposing team’s run games in the early 2010s.
Seattle has tried to stay with that formula as much as they could with corners Mike Jackson and Tariq Woolen, both 6-foot-1 or taller and both weighing in at 210 pounds or more. Woolen is having a fantastic rookie season as well as a coverage corner. Having big corners like that can serve a defense very well. Unless the opposing offensive play caller knows how to put them through a spin cycle.
That’s exactly what Shanahan did on this particular play, and even though the offense did not score here due to a missed field goal, he exploited yet another rule to his advantage based on how Seattle plays closed formations with their corners versus the run.
The play call is a play action wide zone stretch with 2 verticals to the same side. The beauty of the play is in its simplicity. It’s seldom called but when it is, it’s been a big play for the 49ers offense. The two tight ends to the same side as the run action sell the run blocking before releasing downfield.
Seattle is in cover-3 with their strong side corner, Mike Jackson, the force defender up on the line of scrimmage. It is a tough assignment for a corner to execute at the line of scrimmage where there is no detached receiver because the second they realize that it’s not a run play, they have to turn and locate the tight end they’re covering.
Jackson does everything right. He gets outside Kroft when he sees the run fake, that’s what he’s coached to do as the force, to try and turn everything back inside. As soon as he does though, tight end Tyler Kroft runs downfield after the run fake. Jackson is unable to get back and Kroft is wide open for a 28 yard gain.
Shanahan totally dismantled the Seahawks defense in what felt like a tune-up for the final stretch run here into the playoffs. The layers of the offense are starting to come together and the 49ers are putting more and more concepts on tape that defenses have to prepare for.
The beauty of it is we haven’t even seen the wrinkles Shanahan can and likely will add to these concepts in the coming weeks. Perhaps he is saving them for the playoffs. Whatever it is, the NFC defenses are on notice. It’s just a matter of how badly Shanahan can embarrass them too.