Why the Chiefs’ pass defense has become one of the league’s elite units

When you break the Kansas City Chiefs into four parts — rushing offense, passing offense, rushing defense and passing defense — no group has been as consistently productive and impactful as the one facing opposing quarterbacks when they drop back to throw.

Kansas City’s defense has allowed just 6.1 yards per pass attempt — the league’s third-lowest rate. The Chiefs have allowed the second-lowest dropback success rate (39.4%).

Generating these kinds of marks requires all 11 players on the field — but you probably already know how dominant Kansas City’s pass rush has become. Behind them, however, there are (usually) seven players working to make the quarterback hold the ball and fall victim to the pressure

I wanted to highlight how effective the team’s pass coverage has been this season — and how it has fueled an elite pass defense.

Disrupting the offense’s primary weapon

Defensive coordinator Steve Spagnuolo has been straightforward about handling an opponent’s primary pass-catcher. For most of the season, it has been cornerback L’Jarius Sneed’s responsibility to shadow each opponent’s No. 1 receiver — including the Jacksonville Jaguars’ Calvin Ridley, the New York Jets’ Garrett Wilson and the Minnesota Vikings’ Justin Jefferson.

Sneed has been given these opportunities because he possesses a unique combination of physical build and athleticism. This allows him to jam receivers off the line in press coverage — and then keep up with them when they finally get into their routes. His length also makes throwing windows even narrower than they appear.

The most extreme example of Sneed’s effectiveness is this snap against the Jets. Sneed jams Wilson successfully and then sustains his coverage to erase the wideout from the play. Sneed’s coverage also simplifies the read for safety Mike Edwards, which nearly leads to an interception.

Consistently bringing this kind of physicality can have lingering positive effects. It can also lead to penalties; in the Vikings game, Sneed was flagged for getting too rough. But Jefferson later dropped an easy pass after freeing himself from Sneed’s grasp off the snap.

To put it very simply, Sneed has made these elite receivers work very hard in order to get anything done. This season, opposing quarterbacks have registered a passer rating of only 67.4 when targeting Sneed. That’s the league’s ninth-best mark among all corners with at least 160 coverage snaps — and he’s achieved that against some of the league’s top receivers.

Using safeties to double-team receivers

In Sunday’s game against the Los Angeles Chargers, the plan wasn’t to shadow Keenan Allen — but there was still a carefully laid plan to contain him.

On this early third down, the Chiefs are playing man coverage with cornerback Jaylen Watson lined up outside of Allen. Inside, safety Bryan Cook comes down to bracket the dynamic wideout. As Allen works downfield, the coverage becomes a true double-team, which leads to a sack when Justin Herbert can’t find room to complete the pass.

Situationally, this has also been a common strategy for the Chiefs: essentially double-teaming the primary receiver.

That was the game plan against Jacksonville when they were in the red zone, when the Chiefs prevented a touchdown on four separate drives. With Sneed on Ridley, Cook either helped over the top or came down to bracket inside Sneed’s outside leverage.

This left cornerback Trent McDuffie singled up on one of Jacksonville’s secondary wideouts: Zay Jones or Christian Kirk — either of whom McDuffie could blanket. McDuffie has the skills to do that with any team’s second receiver — and it’s the biggest reason the Chiefs can use multiple defenders on the opponent’s top receiver.

Instinctual playmaking

In 2022, there were enough new players in the defensive backfield that it may have led to players leaving playmaking opportunities on the field. It’s clear that this isn’t the case in 2023.

Safety Justin Reid is a great example. After collecting seven passes defended last season, the veteran has already tallied six this year; he currently leads the team. On passing downs, Reid has primarily been used close to the line of scrimmage as a man defender on tight ends. His combination of elusiveness and size gives him an advantage against many of those he faces.

In general, Reid appears to be anticipating plays more often — and covering things more quickly.

On this play against Los Angeles, Reid sees the slant route is coming and jumps it; fortunately for the Chargers, Herbert calmly progresses to his next read.

A quarterback with more undisciplined eyes, however, might not see the safety come up — which would create an opportunity for a turnover.

While Reid has made the majority of his plays closer to the box, free safety Mike Edwards has been flying around the back end of the coverage during his opportunities on the field.

This play against Minnesota reveals Edwards spread out to disguise the one-high look the Chiefs are running — so he’s on the opposite hash from the throw to Jefferson, who is running vertically from the slot. Edwards anticipates the throw, screaming over the top to break it up.

While second-year safety Bryan Cook is likely a better overall player from snap-to-snap, Edwards brings a ball-hawking ability that the Chiefs should continue to utilize when opportunities present themselves.

The bottom line

There are many reasons Kansas City has an elite pass defense. It starts with a dominant pass rush and linebackers who are flying around — but the defensive backfield deserves a lot of the credit. The group’s ability to execute in coverage gives Spagnuolo the opportunity for creativity in the back end — something that we have previously seen only in his pass rush.

It gives Spagnuolo’s unit the highest ceiling it has ever had during the five seasons he has coached in Kansas City.