NFL Analysis

2/12/24

6 min read

Steve Spagnuolo, Chiefs D Had Perfect Plan To Stop 49ers In Super Bowl

Kansas City Chiefs defensive coordinator Steve Spagnuolo
Kansas City Chiefs defensive coordinator Steve Spagnuolo, shown here earlier this season, saw his team execute his master plan vs. the San Francisco 49ers in Super Bowl LVIII. Mandatory Credit: Orlando Ramirez-USA TODAY Sports

It’s too bad the Pro Football Hall of Fame is not open to selecting coordinators. If it were, Steve Spagnuolo would be a lock.

This latest Kansas City Chiefs Super Bowl win gave Spagnuolo a fourth ring and was his most impressive showing as a Chief, in terms of the final game’s performance and, certainly, the season as a whole. Spagnuolo’s dismantling of the 18-0 New England Patriots with the 2007 New York Giants defense remains his crowning achievement.

We hear all the time about Spagnuolo’s pressure packages. Yes, they were heavily featured Sunday night, with the Chiefs sending five-plus rushers on 19 of 44 pass plays. But it never felt like a pressure-centric game because Brock Purdy and the San Francisco 49ers did a mostly stellar job responding to it.

This especially included Cover 0, which Spagnuolo has always featured aggressively and – to the terror of many offensive coordinators – seemingly randomly. The Jauan Jennings 10-yard touchdown came against Cover 0. So did the 24-yard dump-off to Christian McCaffrey in overtime that put San Francisco in scoring position. 

The lack of game-changing pressures was a testament to Purdy and the 49ers, though on perhaps the night’s biggest play – third-and-5 from the Kansas City 35 with two minutes remaining and the Chiefs rolling – pressure did get home, with Trent McDuffie clean to the quarterback for the 16th time this season.

It was Kansas City’s most patented blitz: McDuffie from the slot attacking the B gap with the Chiefs showing quarters behind it. However, the coverage was actually man-free, which Purdy correctly read and then targeted Brandon Aiyuk. McDuffie’s clean path and ensuing pass deflection saved the day. 

Prior to that, the contest had been close thanks not to Kansas City’s pressures, but its coverage.

"Man, it was just tough," Purdy said after the game. "I feel like first and second down was tough. I feel like it was (always) third and long. (The Chiefs) were just sticky across the board when they played man coverage."

The beauty was some of the man coverage came within zone principles. Several times, the Chiefs featured a man outside and a match-zone inside – a smart combination against a 49ers offense designed around throwing between the numbers.

The Chiefs did this out of split safety and single-high looks, which they would rotate to out of split safety after the snap. Thanks to aggressive safety play, on several snaps, it never became fully clear whether it was split safety or single-high.

This (defense) is a special unit. And Spags (defensive coordinator Steve Spagnuolo), man, Spags has been amazing.

Chiefs defensive lineman Chris Jones

“We just played tough, physical, fundamentally sound defense,” said safety Justin Reid, who was featured as the aggressor in many zone looks and handled either Kyle Juszczyk or George Kittle (depending on the circumstances) in man coverage much of the night. “And when you have 11 dogs on the field doing that, good things tend to happen.”

Besides different rotations and zone-match principles inside, Spagnuolo also had LB Nick Bolton chase deep vertical routes down the middle of the field in quarters coverage, almost as if it were Tampa 2. That’s not unheard of, but it’s also not common.

It allowed both safeties to remain in the seams in quarters positioning, combatting San Francisco’s in-breaking routes. To their credit, the 49ers still hit plenty of those deep-intermediate in-breakers against initial quarters looks, especially in the first half. Still, nothing came easy, which took a subtle toll on the offense.

Another thing Spagnuolo did was diversify how he used All-Pro caliber CB L’Jarius Sneed. While Deebo Samuel is San Francisco’s top all-around playmaking receiver, the 49ers’ top pure wide receiver is Aiyuk. Some expected he would draw Sneed, and he did in many man coverage situations.

But there were also instances where Sneed took Jennings. Or where he played the boundary in normal first- or second-down situations. Or the field on changeup calls. Maybe that’s just how it looked; it’s impossible to get a clear read on Sneed’s usage without rewatching the game with a lens entirely on him, which was probably Spagnuolo’s exact intention.

As great as shrewd defensive scheming can be, none of it matters if your guys can’t tackle. That’s what remains so impressive about Spagnuolo’s Chiefs: they are schematically diverse and complex yet still fundamentally sound.

For the first time all season, the 49ers had no runs more than 12 yards. They also did not generate blown defensive assignments with their various motions at the snap. The Chiefs successfully chased those motions in man and bumped the assignments in zone. 

It was a sterling performance against a 49ers offense that, by many metrics (and especially in “21” personnel), is one of the greatest in recent memory.

But here’s what’s so great about the NFL and Spagnuolo, who is one of the most humble and gracious men in the game, would almost certainly agree with this.

The line between success and failure is razor-thin. The 49ers were moving the ball on Kansas City in overtime. If not for RG Spencer Burford making a mental mistake on third-and-4 at the Chiefs 9 that allowed Chris Jones to pressure Purdy, Jennings immediately would have likely scored a touchdown on a pivot route that had beaten CB Jaylen Watson.

Of course, we can apply some version of this woulda/coulda analysis to just about any snap. A broader piece of analysis: the Chiefs, with their offense struggling for much of the game, would have never even made it to overtime without Spagnuolo’s defense. In that sense, the game's flow was a microcosm of Kansas City’s season.

>>READ: Chiefs' Defense Was Super Bowl MVP

Patrick Mahomes was a deserving MVP Sunday night and is unquestionably the NFL’s greatest active quarterback. And, what’s also true: Mahomes’ third ring came for a Chiefs team that was led by its tremendous defense. 


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