Have the Chiefs pulled off a defensive overhaul in one year?

For the defense, the conclusion to the Kansas City Chiefs’ 23-16 victory over the New England Patriots was poetic justice.

In both of the 2018 matchups between these teams, a throw to Patriots wide receiver Julian Edelman meant trouble. Nine of his 11 total catches in those games resulted in first downs — including multiple third-down conversions in overtime of the AFC championship.

The most frustrating part was how similar the big plays were. Edelman would run the same route. Each time, a beaten Chiefs cornerback would throw up his arms in frustration. These plays came to symbolize the 2018 Chiefs defense.

The final play of Sunday’s game was also symbolic.

The Patriots were down by seven with a minute to go. They had a fourth down on the Kansas City 5-yard line. Edelman ran to the left sideline of the Gillette Stadium end zone, where there is a large sign reading, “Brady’s Corner.” But the pass from New England quarterback Tom Brady was knocked down by Chiefs cornerback Bashaud Breeland, who sealed the win with a memorably athletic clutch play.

This dominant performance was a microcosm of the Chiefs’ notable defensive improvement this season — and reminds us that the offseason overhaul of the team’s defensive staff and personnel was completely justified.

Photo by Matthew J. Lee/The Boston Globe via Getty Images

The hiring of defensive coordinator Steve Spagnuolo is paying off in noticeable ways on the field. One of them is his utilization of blitzes, which has been a key to the defense’s success.

The 2019 Chiefs have blitzed on 24.1% of their plays. In 2018, they rushed only 20.7% of the time, because they could rely on the ability of their pass rushers. The problem was that good offensive lines — and good quarterbacks — could neutralize that. Last season, the Chiefs pass rush was only able to sack or hit Patriots quarterback Tom Brady three times in two games. On Sunday — without Dee Ford and Justin Houston — the Chiefs doubled that number.

Against the Patriots, Spagnuolo also demonstrated the impact that calling aggressive and unpredictable blitzes can have.

With 54 seconds until halftime, the Patriots took possession in good field position at their own 41-yard line. On the first play, Spagnuolo surprised them with extra rushers, forcing Brady to quickly dump it off over the middle for a short gain; the quick pressure had prevented him from getting it to a receiver on the sideline to stop the clock. New England wasted 20 seconds hurrying up to the line — and that led to no points before intermission.

This is quite a turnaround from Bob Sutton’s defense, which in that situation would likely have rushed three and dropped eight into coverage.

The personnel changes also proved their value against the Patriots. Breeland — signed as a free agent in the offseason — not only had the game-winning play, but a very significant interception earlier in the game.

You can bet that Spagnuolo dialed up the disguised coverage with this route combination in mind. He knew Brady would recognize press-man coverage on Edelman — and understand that a window would open up for his tight end. Instead, the Chiefs ended up in a zone coverage that allowed Breeland to be in perfect position to undercut the route.

This is also in stark contrast to the 2018 Chiefs defense; neither the defensive backs or their coverages fooled Brady.

Sunday’s victory was the second week in a row that a secondary player made a play that appeared to have come from preparative film study. In Week 13 against the Oakland Raiders, it was safety Tyrann Mathieu who came off his route to intercept a pass. He spoke about how coaches set up the unit for success.

“I just felt like the whole week, we really prepared the right way,” he said. “I felt like our coaches really put everything on the table for us — and I don’t really think we had many surprises today.”

Chiefs safeties were picked on during the 2018 AFC title game. They were targeted in coverage 12 times, allowing nine catches for 119 yards. But on Sunday, Mathieu and rookie Juan Thornhill allowed only seven catches for 53 yards on nine targets. They also limited Patriots running back James White to just 12 yards on his four targets covered by safeties.

Paul Rutherford-USA TODAY Sports

Mathieu has become the vocal leader of the secondary

“You’ve got the good leaders,” said Chiefs head coach Andy Reid during his conference call on Monday. “You mention Tyrann — he’s one of those guys. He unites people and brings them together. At the same time, he has a unique way of being able to challenge guys — including himself. He’s not afraid if he makes a mistake... That attitude is infectious, so I appreciate that.”

The Chiefs desperately needed a leader in 2018. While dealing with his nagging heel injury, former Chiefs safety Eric Berry was unable to provide that leadership from the sidelines. The Chiefs might have been able to count on other veterans like former Chiefs cornerback Orlando Scandrick, but in recent weeks, Scandrick’s public comments about his former teams suggest his veteran presence may have been more negative than positive.

But Mathieu isn’t the only offseason addition who has become a defensive leader. Defensive end Frank Clark had a productive game against the Patriots with a sack and a couple of pressures — including a rush off of the edge that forced Brady into an off-balance throw on the last defensive play. He is vocal — but in Week 14, Clark also led by example, playing with an illness and still making a big impact on the game.

“You see guys like Frank Clark,” said Reid. “He’s had the flu. He had it, going out there he had it where he just wasn’t feeling very well. Son of a buck, he just [found] a way to come through. He hoots and hollers at me, ‘I want to play more!’ How great is that? That attitude — I want to be out there, I want to help, I don’t feel very good, but I’m going, I’m ready to go. That’s infectious.”

Photo by Maddie Meyer/Getty Images

That resilience is refreshing to Chiefs fans. Many have questioned whether Clark is worth the investment over former Chiefs pass rusher Dee Ford. But Clark — while battling his own injuries — has had more than twice as many snaps as Ford, who is now with the San Francisco 49ers. Ford recently re-aggravated a hamstring injury that will keep him out for the foreseeable future.

But according to Reid, the improved defense — and its leadership — has had another effect: improved chemistry on the whole team. The offense and defense can lean on each other.

“Yeah, I love the way that there’s no wall in the locker room,” he said. “They’re always supporting each other. [They] feel comfortable around each other... They challenge each other.”

Reid’s comment about the absence of a wall between the offense and defense suggests that last season, one might have existed. If there was, the Chiefs didn’t let it become public. But with the overwhelming success of the offense — and the failure of the defense — it’s not hard to believe there could have been a rift between the units.

It’s becoming evident that the 2019 Chiefs are all on the same page. While they may not be clicking on all cylinders in every game, each unit is confident in the other — and fans should be, too. Chiefs general manager Brett Veach deserves credit. His decision to overhaul the defense and make tough personnel decisions has been justified — regardless of how this season ends.