Super Bowl LVIII Recap: 49ers Offense vs. Chiefs Defense

Patrick Mahomes and the offense always get the majority of the attention when talking about the Chiefs. But in Super Bowl LVIII, as the offense was struggling to do anything for the first 3 quarters, it was Steve Spagnuolo’s defense that kept the 49ers from running away with the game. That gave Mahomes and company the opportunity to pull several rabbits out of their hat.

For the 49ers offense, Brock Purdy was not the problem. He wasn’t perfect, but he played well enough to win, especially considering what the Chiefs were throwing at him and how tight their man coverage was throughout the night.

By and large, the plays he wasn’t able to make were more a product of what the Chiefs were doing. Purdy made plenty of big throws in key moments and was sharper than he was in his performances against the Packers and Lions.

That said, he’ll probably want that 3rd-and-5 at the end of regulation back (as will Kyle Shanahan). More on that below.

And speaking of Shanahan, the 49ers were a victim of some of the decision he made. This is particularly true of a few critical plays down the stretch as well as his general approach to the run game. It’s fair to question both the infrequency with which the 49ers ran the ball during certain stretches of the game (something we warned against beforehand) as well as the type of runs they chose to feature.

Let’s get into all of it.

3rd Down

As is often the case, this matchup was won and lost on 3rd down. While the Chiefs were struggling to figure things out offensively, the 49ers just couldn’t sustain drives and put points on the board to seize control of the game. This was largely because of their inability to convert on the money down.

Spagnuolo was aggressive with his coverage and pressure schemes on these most critical snaps all night. He leaned on his DBs in man coverage, and they jammed, disrupted, and smothered 49ers receivers (especially cornerback Trent McDuffie).

Spags’ pressure schemes were a mix of blitzes that either created advantageous 1-on-1’s or led to free rushers. However, he also mixed in timely 3-man rushes with a spy on Brock Purdy several times (particularly 3rd-and-longs).

The Niners ultimately converted just 3 of 12 opportunities (25%), which was well below the 47.5% rate with which they converted during the regular season. And that was the difference in the game.

You could see some examples of Kansas City’s 3rd-down chicanery below. This first play was a 3rd-and-14 on San Francisco’s initial scoring drive. The Chiefs would bring six here: