The Buffalo Bills defense ranked among the best NFL defenses last season. The Bills allowed the second-fewest amount of yards to opponents and led the league in opponent passing yards per game. The Bills also held teams to the least plays per drive and least yards per drive.
Still, head coach Sean McDermott needs the Bills to be better.
"All of it. We have to be better defensively. Last year's defense was last year's defense. This year's defense is a new defense made up by different guys even though there has been a lot of continuity to your point. I say this respectfully, we've got work to do on that side of the ball also," McDermott said.
Now the Bills will have to find a way to maintain the same success with almost the same roster as last season. Here are five ways the Bills defense made progress this offseason:
1. Tremaine Edmunds growing as a leader
Edmunds first year in the NFL went by in a flash and by December of his rookie season he began to earn accolades for his effort on the field. Edmunds was named the Defensive Rookie of the Month for December and recorded 43 tackles, two interceptions and four passes defensed in five games.
As the game slows down for him, there's a bright future for the 2018 first-round pick.
"Probably the biggest thing is the confidence. It's extremely high now and you see it in the way he communicates, he has a much better grasp of what we want to get done on defense and what his role is within that," said defensive coordinator Leslie Frazier.
Edmunds has received help from veterans like Lorenzo Alexander and Kyle Williams.
"I'm trying to leave a legacy for the future Buffalo Bills and a big part of that is how much of a leader Tremaine becomes," Alexander said. "So I'm trying to help that process along as fast as possible."
Throughout OTAs and minicamp, Frazier saw Edmunds as that future leader.
"His ability now to communicate with no hesitation, to know exactly what we're looking for as a coaching staff, you see the evidence in the way he's practicing and the way he's communicating with his teammates, which gives those guys confidence in our middle linebacker," Frazier said.
2. Finding Kyle Williams replacement
The Bills were thrilled when they landed defensive tackle Ed Oliver at No. 9 in the 2019 NFL Draft, but he hasn't earned the starting spot yet, for now that belongs to Jordan Phillips.
Phillips signed a one-year deal with the Bills in March and will now compete with Oliver for the starting three-technique position. Since signing his deal, Phillips has been determined to earn the starting role and prove he's can be a top defensive tackle.
"Buffalo gave me an opportunity and I felt that they should reap the benefits of the success that I'm going to have," Phillips said.
Oliver is no slouch on the second team. The Bills are confident he can contribute as they watched him play throughout the offseason
"Ed's done a really good job up to this point," Frazier said. "I don't think it's been overwhelming for him, with the meetings along with what we're doing on the practice field. You see his quickness, you see his burst. As he continues to get a better grasp on what we're asking him to do on defense, I think you'll see more of his athleticism as well. Up to this point, we've been impressed with what we've seen and we'll just keep watching his maturation over the next few months."
3. Deeper group in the secondary
With Tre'Davious White, Micah Hyde, Jordan Poyer, Levi Wallace already leading the charge for the Bills secondary, Buffalo focused its defensive free agent acquisition effort by adding depth for this group. The Bills brought back E.J. Gaines and added former first-round pick Kevin Johnson to add more competition at the cornerback position.
White, Poyer and Hyde are locks for their starting spots but the competition heats up at the No. 2 cornerback spot and the nickel. Johnson was named a standout for the Bills by ESPN this offseason and second-year corner Siran Neal has been making his presence known as he converts to the nickel spot.
"You saw the ability coming out of college," Frazier said on Johnson. "He did a really good job in his rookie year, off to a really good start. The injuries have kind of creeped up. We're hoping that he can stay healthy, we know he has the talent to really help us."
Wallace still holds his starting spot from last year and earned the highest Pro Football Focus grade of any first-year cornerback, along with the highest coverage grade.
4. Keeping personnel the same
The Bills have stressed continuity and building a familiarity between teammates. It's been tough on the offense with multiple players missing time due to injury but the defense has stayed injury-free throughout OTAs and minicamp.
The Bills first-team defense has stayed relatively the same as last season and the ability to come in and work with the same group has been beneficial for Hyde.
"It's huge for communication purposes," Hyde said. "I know where Poyer is going to be at all times, I know where Tre'Davious, Tremaine, the D-line, same thing. I know what they're going to be in so once you can pinpoint where everybody's going to be and you know your job, the sky's the limit."
Specifically, it's helped Hyde and Poyer. The two safeties describe their play sometimes as "freelance" and are able to give Josh Allen different looks and figure out what works.
"We have a good understanding of what we are doing on the football field," Hyde said. "We're always talking and communicating and that goes for whoever is on the back end. As long as we keep communicating and keep talking we can be a great defense."
As the Bills continue 2019 OTAs, check out photos of each of the 91 players on the team.

David Sills V - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

John Brown - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Stephen Hauschka - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Matt Barkley - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Tyree Jackson - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Cory Carter - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Andre Roberts Buffalo Bills Free Agent Visit New Era Field Orchard Park, NY March 14, 2019. Photo by Sara Schmidle

Corey Bojorquez - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Cole Beasley - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Zay Jones - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Victor Bolden Jr - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Ray-Ray McCloud III - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Da'Mari Scott - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Robert Foster - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Josh Allen - Buffalo Bills, May 15, 2019.
Photo by Sara Schmidle

Chase McLaughlin - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Isaiah McKenzie - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Rafael Bush - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Jordan Poyer - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Marcus Murphy - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Micah Hyde - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Taron Johnson - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Buffalo Bills running back LeSean McCoy (25). Buffalo Bills vs Los Angeles Chargers at New Era Field, September 16, 2018. Photo by Bill Wippert

E.J. Gaines - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Tre'Davious White - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Frank Gore - Buffalo Bills take part in voluntary off-season at One Bills Drive. April 15, 2019. Photo by Bill Wippert

RB T.J. Yeldon (No. 29)

Lafayette Pitts - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Dean Marlowe - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Senorise Perry - Buffalo Bills take part in voluntary off-season at One Bills Drive. April 15, 2019. Photo by Bill Wippert

Siran Neal - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Kevin Johnson - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Denzel Rice - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Ryan Lewis - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Levi Wallace - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Devin Singletary - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Maurice Alexander - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Patrick DiMarco - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Mik'Quan Deane - Buffalo Bills. Photo by Bill Wippert

Deon Lacey - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Christian Wade - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Jaquon Johnson - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Cameron Lewis - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Juwan Foggie - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Tremaine Edmunds - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Vosean Joseph - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Julian Stanford - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Corey Thompson - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Tyrel Dodson - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Eddie Yarbrough - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Jerry Hughes - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Mike Love - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Lorenzo Alexander - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Matt Milano - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Eli Harold - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Mitch Morse - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Spencer Long - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Vladimir Ducasse - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

L.T. Walton - Buffalo Bills.

Garrett McGhin - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Ike Boettger - Buffalo Bills, May 1, 2019.
Photo by Sara Schmidle

Russell Bodine #66. Buffalo Bills 2018 player photos. Photo by Bill Wippert. May 2, 2018.

Quinton Spain - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Conor McDermott - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Reid Ferguson - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Cody Ford - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Jeremiah Sirles - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Dion Dawkins - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

LaAdrian Waddle - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Wyatt Teller - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

Jon Feliciano - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Ty Nsekhe - Buffalo Bills, May 1, 2019. Photo by Sara Schmidle

De'Ondre Wesley - Buffalo Bills. Photo by Bill Wippert.

Jason Croom - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Tyler Kroft - Buffalo Bills, April 30, 2019. Photo by Sara Schmidle

Duke Williams - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Nate Becker - Buffalo Bills.

Lee Smith - Buffalo Bills, May 15, 2019. Photo by Sara Schmidle

Nicholas Easley - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Cam Phillips - Buffalo Bills, May 14, 2019. Photo by Sara Schmidle

Dawson Knox - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Thomas Sweeney - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Shaq Lawson - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Ed Oliver - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Darryl Johnson Jr - Buffalo Bills on May 9, 2019. Photo by Sara Schmidle.

Trent Murphy - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Kyle Peko - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Robert Thomas - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.

Jordan Phillips - Buffalo Bills, May 14, 2019.
Photo by Sara Schmidle

Star Lotulelei, DT (No. 98)

Harrison Phillips - Buffalo Bills, May 8, 2019. Photo by Sara Schmidle.
5. New mindset
Be more physical and be nastier has been McDermott's emphasis to the defense this offseason. McDermott was unimpressed with the physicality of the defense last year and wants it upped for 2019. The main goal that comes with a more physical and nastier defense? More takeaways.
"I'm seeing just a lot of guys flying around, a lot of guys making plays on the ball," linebacker Matt Milano said. "That's been the emphasis is just getting takeaways and making sure everybody's running to the ball because you never know what can happen. Somebody strips it out, whatever it may be, but just good things happen when you do that."
"Knowing the situation and obviously anticipating is really what it comes down to. If you know the situation that you are in, you can anticipate not only what you are going to do but what the opponent is going to do. That gives you a chance to be a step ahead or half a step ahead and, in this case, and that's where turnovers happen," McDermott said. "When we can put people behind the sticks and put us in favorable positions where it's third and long, fourth and long, or second and long, usually when you can do that that's putting pressure on the offense on the opponent and that's where turnovers tend to happen."