For the fourth time in the past five seasons, the Kansas City Chiefs are headed to the Super Bowl. And this might be their most impressive run yet.

In the AFC playoffs, they bludgeoned the Miami Dolphins at home before hitting the road and taking down the Buffalo Bills and Baltimore Ravens. It’s easy to get caught up in the lore of Patrick Mahomes, Travis Kelce, Andy Reid, Taylor Swift and what the Chiefs are doing on offense, but their defense has been a driving force for KC's success this season, particularly in the AFC championship game. Yielding 13.7 points per game against the toughest offenses in the league doesn’t happen by accident and they’re uniquely built to turn the heat on in January.

Chiefs coordinator Steve Spagnuolo comfortably has his best defense during his tenure with the team. For the first time since Spagnuolo took over in 2019, the Chiefs have a truly stifling defense. According to RBSDM.com, the Chiefs rank first in expected points allowed (-0.072) over the 2023 postseason, almost matching their figure from the regular season (-0.076). They’ve been great on first and second downs, forcing teams into poor situations that allows Spagnuolo to be creative with his personnel. The Chiefs held the Ravens to 3-of-11 on third down and kept them out of the end zone for the final three quarters of the game.

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During the pregame and postgame, some Chiefs players sported a T-shirt that read "IN SPAGS WE TRUST," an homage to their defensive leader. The mantra wasn't lost on the team's social media account.

On the field, the Chiefs' defense starts with their defensive line, which has become one of the most talented units in the league. Chris Jones is a force who's capable of detonating offensive lines whenever he feels like. George Karlaftis has really come into his own as a second-year defensive end and the rest of the group has their strengths as well. Losing stud lineman Charles Omenihu for the Super Bowl with a torn ACL will hurt, but they have the overall structure to survive something like this. Never mind that the Chiefs are 1.5-point Super Bowl underdogs against the San Francisco 49ers.

As the Ravens saw firsthand, there might not be a better team that’s able to marry their defensive line talent to a talented coverage unit that’s still incredibly young. L’Jarius Sneed, Trent McDuffie, Jaylen Watson and Joshua Williams are all on their rookie deals (all were drafted in 2022, save for Sneed, who was selected in 2020) and they’re a driving force for the team’s success. McDuffie was an All-Pro player as a slot defender and Sneed is playing as well as any cornerback in the league. According to the NFL’s Next Gen Stats, Sneed ranked fourth in expected points allowed per target (-0.33) among all cornerbacks with at least 300 coverage snaps on the season. He’s about to get paid for a reason this offseason.

That secondary allowed the Chiefs to have an aggressive game plan against Lamar Jackson, who is in line to win his second MVP award. According to the NFL’s Next Gen Stats, Jackson was blitzed on 43.5% of his dropbacks and was under pressure on 37% of them. Outside of one incredible touchdown from Jackson to Zay Flowers in the first quarter, the Chiefs largely held him in check on those plays. That versatility will come in handy as they try to take down the 49ers, who have arguably the most talented supporting cast on offense in the league.

Pairing this level of talent with the experience that Spagnuolo makes it easy to see how the Chiefs have built a championship defense. Hitting on so many recent draft picks, particularly within the secondary, has allowed KC to be one of the most complete defenses in the league. For whatever reason, Spagnuolo isn’t a factor in head-coaching conversations (potentially due to having a 10-38 record with the Rams over a decade ago), which benefits the Chiefs as long as that trend continues.

If the Chiefs win their third Super Bowl with him as coordinator perhaps the narrative will change, but for now, they have a defensive mastermind who's as capable as the star power they boast overall.