49ers Playbook Week 16: How Kyle Shanahan exploited the Jaguars defense

SANTA CLARA, CA - DECEMBER 24: George Kittle #85 of the San Francisco 49ers celebrates after scoring on a eight-yard touchdown catch against the Jacksonville Jaguars during their NFL game at Levi's Stadium on December 24, 2017 in Santa Clara, California. (Photo by Robert Reiners/Getty Images)
SANTA CLARA, CA - DECEMBER 24: George Kittle #85 of the San Francisco 49ers celebrates after scoring on a eight-yard touchdown catch against the Jacksonville Jaguars during their NFL game at Levi's Stadium on December 24, 2017 in Santa Clara, California. (Photo by Robert Reiners/Getty Images) /

This week’s installment of 49ers Playbook is a long one and looks at how head coach Kyle Shanahan schemed to beat the Jaguars’ No. 1 defense in the league last Sunday.

Last Sunday’s week 16 matchup against the Jaguars was one of the marquee games of the weekend as the 49ers, who were winners of four of their last five games faced the Jaguars in Santa Clara. It was a coaching clinic as Kyle Shanahan out-schemed Jaguars defensive coordinator Todd Wash.

Heading into the game, the Jaguars defense was being touted as the #1 defense in the league by all metrics, including Football Outsiders DVOA, despite being 27th against the run in the same metric. It made sense then that the game plan reflected this discrepancy.

Shanahan’s heavy reliance on 21 personnel (two running backs, one tight end, two receivers) combined with a lot motion exploited a lot of gaps in coverage and weak one-on-one matchups with certain personnel in the Jaguars defense.

Three ways Shanahan schemed to beat the Jaguars defense were 1) reliance on the outside zone to set up play action, 2) using the run to exploit matchups with weaker defenders and revealing tendencies, and 3) stretching the field horizontally and vertically to open voids in the middle of the defense.

Each play in each sequence is used to build on the next play below it in each section, displaying the kind offensive genius this team has not had in a few years.


The very first drive of the game was instructive for how the 49ers would scheme the remainder of the game. The very first play of the game revealed a tendency the 49ers would exploit regularly after that point, including on the same drive.

The 49ers are running outside zone and initially show a trips bunch to the right of the formation before Garappolo motions tight end Garrett Celek with a “Y-trade” motion over the to the left. Prior to the motion, the Jaguars edge defender lines up in a wide-9 technique several yards outside the tackle Joe Staley.

After the motion, the edge defender slides down inside the C-gap between Celek and Staley. Safety Barry Church follows the motion of Celek to the opposite side and is responsible for crashing the outside D-gap.

The snap reveals the tendency of the Jaguars to crash the end hard in the C-gap and D-gap, regardless of which way the play goes. The run is insignificant as far as the stat sheet goes, as Hyde loses one yard but is very revealing as to how the Jaguars would play that scheme.

Later in the same drive, the 49ers lineup in 22 personnel (two backs, two tight ends, one receiver) with fullback Kyle Juszczyk offset behind Celek on the right.

With the heavy formation with tight ends at both ends, the Jaguars edge defenders are lined up in the C-gaps with outside defenders setting the D-gaps. It is 1st down and the Jaguars are probably expecting the 49ers to run (a common 1st down tendency) but the 49ers have a bootleg pass called.

The previous tendency in the first play above is revealed again at the snap and Shanahan exploits it perfectly. The outside zone motion to the right gets the backside edge and safety to crash the edge and follow the direction of the play as Juszczyk leaks out across the formation to the left.

By this point, the entire defense is caught with their backs turned and following the direction of the fake run while Garoppolo boots left and dumps off to wide open Juszczyk for a 17 yard gain. Note the defenders with their backs turned as the catch run goes for a big gain.


Another way Shanahan exploited the Jaguars weaknesses was the heavy reliance on 22 and 21 personnel formations. Kyle Juszczyk was on the field for 56% of the offensive snaps, his 2nd highest percentage of snaps this season.

These personnel groupings utilized basic motions across the formation. It wasn’t anything that was overly complicated, but Jaguars linebacker Paul Posluszny’s post-game comments were very instructive:

"“But they did all the hard s—, the stuff that stresses our defense. They know our defense so well, and they kept us off balance. They’d run the ball with the Y (receiver) coming across the formation; they’d run a play that looked like a boot, and then they’d run the boot, and a whole lot of other stuff that is difficult for us to defend.”"

The 49ers used a lot of “Y-trade” motion where the tight end simply just switches sides of the formation. One simple motion caused all kinds of confusion for the Jaguars as they seemed unprepared to deal with the shifts. The colors in the above image note all the shifts.

In 21 personnel, the strength of the formation is set to the right with Celek as the inline tight end. However, as he motions, the entire defensive front shifts with every single player switching gaps and assignments to the opposite side.

The 49ers still run the inside zone away from the motion. It’s likely they just wanted to shift the strength of the strong side defenders away from the run and they end up picking up six yards anyways.

Another way Shanahan caused confusion and revealed tendencies was by using split zone sift block misdirection.

While a not a pre-snap motion, the sift block on the split zone utilizes a play side blocker who comes across the formation to kick out the edge defender on the backside to open a running lane.

The defense follows the split zone motion at the snap as well as the end around motion by Bourne but the zone run goes again goes away from the misdirection and to the weak side.

The flow of the defense causes a running lane to open up in the middle of the field and running back Matt Breida goes for a six-yard gain.

Combining the personnel grouping, the Y-trade motion, and the split zone blocking, in the 2nd quarter the 49ers capitalize big time on the confusion and one-on-one matchup.

The defensive target the 49ers go after is Posluzsny and the aggressiveness of reading what appears to Posluszny to be a lead block as well as the split zone block. The play is a variation of the tight end throwback pass Shanahan used frequently with the Falcons, except he utilizes the fullback on the wheel route.

With Posluszny eyes trained on Juszczyk coming of the backfield, the rest of the underneath defense follows the split zone sift and Garoppolo as he partially rolls to his right.

The defense is stretched horizontally and vertically by the play action and deep curl routes and Posluzsny gets caught in the open playing the run while Juszczyk runs right by him on the wheel route down the sideline.

Garoppolo drops in a dime from the opposite hash and the play goes for 44 yards.


This season the Jaguars have the #1 pass defense and a secondary that consists of corners Jalen Ramsey and AJ Bouye, and safeties Barry Church and Tashaun Gipson. It made sense then that the 49ers would not spend a great deal of time attacking those matchups.

Instead, Shanahan elected to stretch the defense and put middle defenders in conflict by utilizing a combination of routes that stretched the coverage both vertically and horizontally and occupied defender’s zones so they could not adequately jump other routes.

As was the case all game, the 49ers primarily stuck to attacking Posluzsny over the middle. The 49ers are running a variation of the cross country dagger concept I covered here a few weeks ago. Instead running it out of a 2 receiver bunch, they utilize the tight end/receiver combo from the right.

At the snap, Posluzsny gains depth with the vertical routes as Kittle runs the Y-cross and draws the attention of the far safety. The flat route pulls another underneath defender out with it. The deep corner also shadows Louis Murphy running the deep dig route behind the Y-cross.

Posluzsny is put into conflict by Hyde coming out of the backfield on the checkdown and he takes a step toward Hyde, opening a window just long enough to hit Murphy over the middle in the vacated zone.

On a key scoring drive late in the game, the 49ers lineup in 11 personnel and use motion to spread the defense out across the field, who are in a cover 2 shell.

The motion puts Trent Taylor in the middle of a trips formation to the left and shifts the middle defenders out away from the middle of the field.

The trips receivers are running a drive route underneath two deep curl routes designed to stretch the middle of the field. Hyde and Kittle are running what appear to the Jaguars to be a flat-7 route combo as evidenced by the leverage the defenders play.

But Hyde runs the Texas route and gives the defender an outside move before cutting in. The deep curls have drawn the attention of the defenders as they have vacated their zones. Hyde’s outside move frees him over the middle for Garoppolo to deliver a strike as the 49ers move into scoring position.

The combination of personnel groupings, motions, and route concepts gave the 49ers their signature win of the season over a top playoff team. Every play is building block to something more complicated as it reveals the defense’s tendencies and allows Shanahan to scheme to those tendencies.

Next: 49ers will make the playoffs in 2018

The result was that they put together what was perhaps the best performance and showcased exactly fans can expect out of this team in the future.