Is the Bills' No. 1 defense for real? Facing Chiefs' Patrick Mahomes will provide answers

ORCHARD PARK, N.Y. -- The Buffalo Bills have never intercepted quarterback Patrick Mahomes.

The Bills have played the Kansas City Chiefs twice since Mahomes became their starter in 2018 -- once in the regular season last year and again in last season's AFC Championship Game. In those games combined, the MVP of Super Bowl LIV completed 78.1% of his passes, averaging 8.6 yards per attempt, and threw five touchdowns and no interceptions.

Mahomes was sacked once in each game and had a combined off-target percentage of 6.3% -- the lowest against any team the quarterback has faced in his career. When the teams meet Sunday night (8:20 p.m. ET, NBC), the Bills hope to change those numbers.

How do you force Mahomes to do something he doesn’t want to do and turn the ball over?

“The front. The rush,” Bills nickel corner Taron Johnson told ESPN. “I mean, hopefully our rush does what it's been doing and, if they do that, it's a beautiful thing.”

The Bills have 12 sacks this season, tied for sixth-most in the NFL. Their defense is ranked No. 1 in the NFL and has two shutouts. While the unit's numbers jump off the page -- 216.8 yards and 11 points allowed per game and 11 takeaways (all league-bests) -- the team has faced three backup quarterbacks in the past three games.

Is this defense enough to take down Mahomes and the back-to-back AFC Champions?

“[The Chiefs] are kind of the gold standard, what you would want to be as an AFC team, being to the AFC Championship the last three years and competing for Super Bowls is what they've been doing,” quarterback Josh Allen said. “That's what every team wants to be and until somebody knocks them off in the playoffs, that won't change.”

The Bills worked this offseason to build a team that could do just that.

A revamped defensive end room

Among the offseason conversations had between general manager Brandon Beane, coach Sean McDermott and others in the Bills organization was the need to bolster the pass rush -- no player finished with more than five sacks in 2020 -- and increase the size of the defensive line.

In 2020, the Bills had the lowest average weight among starting defensive ends, defensive tackles and nose tackles in the NFL (280 pounds), per the Elias Sports Bureau. It didn't help that 315-pound defensive tackle Star Lotulelei opted out of last season due to concerns related to COVID-19.

The team addressed those two concerns in a big way this offseason, using its first two draft picks on edge rushers -- Greg Rousseau (6-foot-6, 266 pounds) and Boogie Basham (6-3, 281).

“Those guys have given us an infusion of youth, along with talent,” defensive coordinator Leslie Frazier told ESPN. “But they've also increased our size... Now, we look more like a National Football League defensive line. It's a big difference.”

Rousseau is tied for the team lead with 2.0 sacks and leads all Bills defensive ends in snaps played this year (54.5%), while Basham has been active once in part due to the depth on the defensive line.

"An opposing pass rush can completely change the dynamics of a football game against any quarterback in this league," ESPN NFL analyst Matt Bowen said. "That's what the Bills [were] trying to build this offseason.”

Mahomes, the NFL QBR leader at 82.9, will present a different challenge for this group.

“He can hit every receiver on the field. It doesn't matter if he's rolling out to his arm side or away from his arm, I mean, the guy can make passes without even looking at people,” said defensive end Jerry Hughes, who has not watched last year's AFC Championship Game loss to the Chiefs. “When you can do something like that at this level, it's hard to slow someone down.”

The Bills' sack rate has increased from 5.9% in 2020 to 8.4% this year. However, the team ranked second in pass rush win rate, an ESPN metric powered by NFL Next Gen Stats, last season (52%) and are around the same mark this season 48% (10th).

Relative to the Chiefs’ pass block win rate, 59% (14th), the Bills may have some room with which to work. The interior of both lines is playing well statistically. Defensive tackle Ed Oliver and Lotulelei, who has been one of the team's best pass-rushers (2.0 sacks), are off to good starts (13% and 17% pass rush win rates, respectively), while Hughes and Mario Addison have been solid. The Chiefs, however, have allowed five sacks this season and the Bills' defensive line as a whole has yet to show significant improvement.

Blitzing, will not be the answer, either. Mahomes is completing 68% of his passes against the blitz (eighth best in the NFL). The Bills defense has also not blitzed much this season (33 of 157 plays).

“If you're going to have success against Mahomes, you have to be able to play coverage over the top, limit deep balls, and put pressure on him with four,” Bowen said.

Steps forward

Along with the return of Lotulelei and the new additions on defense, 2020 second-round pick A.J. Epenesa has taken a step forward and is down about 20 pounds from last season.

“[Epenesa] has completely transformed his game in terms of his body type,” Bowen said. “I think he's playing faster on the tape. He's always been a technician, you saw that at the University of Iowa, he's excellent with his hands, but now you're seeing more juice off the football. That's allowing him to gain an edge on offensive tackles, or loop inside and twist and close with speed to the quarterback.”

Epenesa is questionable for the game against the Chiefs with a foot injury suffered in Thursday’s practice. He was limited Thursday and Friday.

The defensive end leads the NFL in pass rush get off -- the average time it takes a pass-rusher to cross the line of scrimmage after the snap -- this season (0.68 seconds). While he doesn't have gaudy stats, he has been jumping off the tape.

Multiple players and coaches have noted he is more comfortable with the scheme and his play in Year 2.

“He just seems to be more confident with what we're asking him to do, and you can see it in his movement, and the confidence that he's displayed on the field, his abilities,” Frazier said. “That's something we really needed to see, an area where we really needed to see him grow in his maturity on the field, as well as off the field.”

Despite the top rankings, this version of the Bills defense has room to grow. To slow down the Chiefs offense, the Bills’ reworked defensive front will have to get more pressure than the 21.1% quarterback contact percentage it had in two losses to the Chiefs last season.

And while a game against Mahomes & Co. will be viewed as a measuring stick, not everyone is worried about the long-term success of this defense based on the outcome in Week 5.

“I could just see us growing and getting better and that's what we always talked about,” Hughes said. “It's not playing our best ball now. We're going to do that down the road in December, January, leading up to the big games.”