On Thursday, we considered the three biggest questions for the Kansas City Chiefs’ offense in the Super Bowl against the San Francisco 49ers. Now let’s direct our attention to the biggest questions for the Kansas City defense.
1. How should the Chiefs align against the 49ers’ 21 personnel?
When playing the San Francisco offense, the first question is regarding how you align against their 21 personnel packages (two running backs and one tight end). Through the NFC Championship, the 49ers used 21 personnel 38% of the time, which is unheard of in today’s NFL. It’s their second most-used personnel grouping, trailing 11 personnel at 40%. In 21 personnel, the 49ers average 0.06 EPA per play while passing on 52% of the snaps.
When the 49ers put George Kittle, Brandon Aiyuk, Deebo Samuel, Christian McCaffrey and Kyle Juszczyk on the field, they are forcing the defense to choose between its base and nickel alignments. Against a base defense, San Francisco can succeed with passing plays — and if the defense is in nickel, the 49ers can win by running the ball. Since every one of these skill players is quite versatile, San Francisco can get into just about any look or play-call when they are on the field.
After dealing with this kind of thing for three straight playoff games, the Chiefs have a lot of experience with this problem — but I still want to see how defensive coordinator Steve Spagnuolo deals with it. Does he stay in his base defense, trusting his linebackers and safeties to cover in space? Or does he put Trent McDuffie in the slot and hope the run defense will hold up?
Everything the 49ers do revolves around this 21 personnel group. Spagnuolo will have to craft an awesome game plan to counter it.
2. Without Charles Omenihu, can the Chiefs crush the pocket?
One area where postseason defenses have gained an edge against the 49ers is collapsing the pocket around quarterback Brock Purdy — particularly with power. While the San Francisco offense feels like the Death Star, its one vulnerability is the offensive line’s pass-protection ability. Head coach Kyle Shanahan generally tends to emphasize skill players over blockers. That seldom matters in the regular season — but in the postseason, it can matter a lot.
A shorter, smaller quarterback, Purdy is just athletic enough to scramble and make plays in space — but within the pocket, he’s very poor at dealing with pressure. Both the Lions and Packers were able to collapse the pocket around him with bull rushes, causing Purdy to drop his eyes.
For the Chiefs, this would’ve been a perfect opening for defensive end Charles Omenihu. His length and power — not to mention his familiarity with his former team’s offensive line — would’ve been huge. But he will miss the game after tearing an ACL in the AFC Championship game.
Just the same, Kansas City will have a talent advantage up front. Who will step up to collapse the pocket? Both Mike Danna and George Karlaftis have struggled while rushing only with power; both are junkball pass rushers who like to throw a lot at you. Some of this can be mitigated by Chris Jones destroying the interior of San Francisco’s offensive line — but the defensive ends will still have to make their presence felt.
Aside from left tackle Trent Williams, however, the 49ers’ offensive line is weak. Could Danna and Karlaftis get the job done? Or might we even see Jones aligned on the outside more often, leveraging his length and power?
3. Can the Chiefs force Purdy to turn the ball over?
I could write an entire dissertation about Purdy. For a year and a half, he’s operated the 49ers’ offense as it achieved statistical dominance. He deserves part of the credit for that. But conversations about him tend to be insane — because many people have failed to evaluate him correctly.
Purdy is considered to be a game manager — but that just isn’t what he does. He’s a short quarterback with relatively poor arm strength. He doesn’t like to operate in the pocket; he thrives while playing out of structure and in chaos. But because Shanahan has built such a box with his scheme and offensive personnel, the offense doesn’t need him to do that very often.
Still, when Purdy gets into that tendency, he adds that layer to the offense — something that Jimmy Garappolo could never do. But that layer comes with a significant cost.
Purdy is considered to be a quarterback who keeps the ball safe — but that is simply inaccurate. Including 2023’s regular season and postseason, Pro Football Focus says Purdy is tied for the fifth-most turnover-worthy plays. Of quarterbacks with at least 300 dropbacks, Purdy ranks eighth in turnover-worthy play percentage. Against pressure, Purdy is tied for fourth in plays and seventh in percentage with 300 or more dropbacks.
Purdy’s turnovers tend to come against elite defenses, which can capitalize on his mistakes in ways that bad defenses cannot do. Purdy threw four interceptions against the Baltimore Ravens, two against both the Minnesota Vikings and Cincinnati Bengals and one against the Cleveland Browns.
Can the Chiefs force him into that mode? Early in the game, can the Kansas City defense create enough pressure to rattle him? Can it force opportunities for turnovers — and then capitalize on them?
If the Chiefs can force turnovers, they could be well on the way to a sizable win. They will, however, need to take advantage of the opportunities Purdy gives them — and keep San Francisco’s skill position players ineffective through four quarters.