Prior to the 3rd-and-15 that will live in Super Bowl lore, the 49ers had done the unthinkable, all but shutting down the Chiefs’ dangerous passing attack. Patrick Mahomes had completed 19 of 32 passes for only 181 yards, no touchdowns, and 2 interceptions. Kansas City had just 10 points on the board. With the exception of one 28-yard reception by Sammy Watkins in the 2nd quarter, the 49ers had taken away the big play. So how did they do it? And what changed in the 4th quarter?

Robert Saleh’s Coverage Choices

The 49ers are a zone-coverage defense that leans heavily on Cover-3 variations. Against the Chiefs, though, Defensive Coordinator Robert Saleh made the decision to predominantly play Quarters coverage (or Cover-4).

At a very basic level, the difference between Cover-3 and Quarters is simple. Cover-3 calls for 3 deep defenders (each responsible for a third of the field) and 4 men underneath. Quarters calls for 4 deep defenders (each responsible for a quarter of the field) and 3 men underneath. Saleh’s approach was to try and take away Kansas City’s downfield passing game with the extra deep defender.

Below is a look at one of the ways the 49ers played Quarters and took away the deep ball. This particular snap was Cover-4 “Lock.” This meant the backside cornerback, Richard Sherman, would play man-to-man against his receiver, while the rest of the defense would play the Quarters zone coverage.

The “Lock” call was used throughout the night against Kansas City’s 3×1 sets, and it enabled the underneath coverage to push more to the 3-receiver side, as you can see on this play. That meant the 49ers were able to defend the deep ball while also ensuring that their underneath coverage could better account for intermediate-level routes.

Saleh’s preferred coverage choice on the night worked. Out of 50 called pass plays (not including the final incompletion meant to run out the clock), the 49ers played zone 37 times. 29 of those were Quarters variations. Mahomes finished just 13 of 23 for 86 yards on these plays. That’s 3.74 yards per pass attempt. If you include his 4 scrambles for 33 yards and 2 sacks for -10, the Chiefs were held to just 109 total yards on 29 called pass plays against this coverage. That’s a staggering 3.76 yards per play.

Mahomes Was Off His Game

Mahomes slowly began losing his patience and precision in the 3rd quarter. On the below sack-fumble, he had Travis Kelce wide open for a first down in the flat to his left but didn’t pull the trigger.

One play later, he forced a bad throw to Tyreek Hill that resulted in an interception.

I’m not sure exactly what happened there. Mahomes had a chance if he threw Hill open inside, although the window wasn’t huge. This was just a bad, forced pass that almost looked like it was attempted out of frustration. An uncharacteristic mistake for a quarterback who is normally careful with the football.

Mahomes’ 2nd interception appeared to be the final nail in Kansas City’s coffin. At first glance, this looked like another terrible throw.

To be fair to Mahomes, he was trying to put this ball on Hill’s back-shoulder with safety Jaquiski Tartt closing from the other side of the field. Still, that type of throw needed to be put a little more on Hill’s body.

2-3 Jet Chip Wasp

With just over 7 minutes remaining and trailing 20-10, the Chiefs faced a 3rd-and-15 from their own 35-yard line. A stop on this drive likely wins the game for the 49ers. As we all know, the 49ers did not get that stop, and the play-call “2-3 Jet Chip Wasp” was the reason why. I broke down this play in detail here. It is one that that will live in infamy in 49ers history.

One aspect of this play that might deserve some second-guessing is the fact that Saleh decided to play Cover-3 in this situation. Given how successful San Francisco was all night at taking away the big play with Quarters coverage, you have to wonder if he regrets this play-call.

Going back to our previous explanation, Cover-3 is a 3-deep 4-under look, while Cover-4 is a 4-deep 3-under look. With that said, the thought process behind switching to Cover-3 on this play does make some sense. It was 3rd-and-15, and Saleh wanted 4 defenders underneath around the first-down marker.

Not to mention, the 49ers have been great all year at living in Cover-3 and not giving up the big play. If this was a mistake by Saleh, it wasn’t an egregious one. However, one can’t help but think that the outcome of the game would have been different if the 49ers went with Quarters coverage instead.

4 plays later, the Chiefs cut the 49ers’ lead to 3 points.

Sammy Watkins vs. Richard Sherman

The big play on Kansas City’s go-ahead touchdown drive also came against a single-high look. The 49ers brought a 5-man pressure here and left their cornerbacks alone on an island in man coverage. That left Sammy Watkins against Richard Sherman to Mahomes’ right. From a movement and athleticism standpoint, that’s an advantageous matchup for the Chiefs. Mahomes saw the 1-on-1 and pounced.

That’s a great job by Watkins of creating separation off the line and an absolutely perfect throw by Mahomes.

The Game-Winning Touchdown

To take the lead, Andy Reid called a play that built off of the Chiefs’ tendency to use Tyreek Hill on shovel passes in the red zone. First, take a look at Hill’s touchdown on a shovel pass against the Titans in the AFC Championship Game.

Hill is too fast for any defender to try and chase him across the field like his man did here. The 49ers came into the Super Bowl prepared to play this a bit differently.

Here, the 49ers were playing 0-man coverage and bringing 6 pass rushers. Below, you can see Hill and Damien Williams aligned in the backfield, along with the matchups.

The way the 49ers were defending this was for safeties Jimmie Ward and Jaquiski Tartt to play the releases out of the backfield. That way, instead of Ward chasing Hill across the field if K.C. ran a shovel pass, Tartt could just cut him off.

When Hill moved right to left in front of Mahomes at the snap, faking the shovel-pass, Tartt moved left to cut Hill off. Ward was then responsible for Williams to the right. However, Ward had to wait and read Hill’s movement first. The initial fake to Hill forced Ward to take a couple of false steps inside. That, along with the traffic created by Travis Kelce’s route, was enough to allow Williams to outflank Ward to the edge. Richard Sherman made a great effort after coming off of Kelce, but Williams had enough of an angle to get in the end zone.

That’s another great play-design and play-call by Andy Reid. He is so good at setting up tendencies and then breaking them at the right moment.

“Great players aren’t always great. They’re just great when they have to be.”

The above quote is one you can hear uttered by John Facenda during numerous NFL Films Super Bowl highlights. It certainly applied to Patrick Mahomes in Super Bowl LIV. Mahomes did not have a great first 3 ½ quarters. It wasn’t as bad as it initially appeared while watching live on Sunday, but it was not what we’re used to seeing out of the best quarterback in the NFL. The 49ers’ approach was a big reason for that.

His final 7 ½ minutes of the 4th quarter were fantastic. My initial thoughts after the game were that Damien Williams should have been the MVP. Upon review of the All-22, though, it’s clear that Kansas City doesn’t win this game without Mahomes. He made some big time throws when his team needed them most. The Chiefs are Super Bowl champions as a result.

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