The Bills officially introduced new defensive coordinator Jim Leonhard on Thursday from One Bills Drive.
Leonhard spent over 30 minutes breaking down his fit in Buffalo, his scheme and observations on the roster, among other topics.
How will Buffalo's scheme change?
Part of what Leonhard will bring from a schematic standpoint is a change in defensive identity.
Buffalo's defense operated in a 4-3 base (four defensive lineman, three linebackers) and an emphasis on nickel defense (two linebackers with a fifth defensive back replacing a LB) under former head coach Sean McDermott. Leonhard's base defense is a 3-4 alignment: three defensive lineman and four linebackers (two inside, two outside) with the outside backers having both rush and coverage ability.
"It's going to be a change for them, but we're excited as a coaching staff to really be able to create something that is best for their skill sets and fits their personalities," Leonhard said.
The new scheme can be helpful for generating pressure on the quarterback as it gives greater flexibility to rush with five players. As such, Buffalo will have separate inside linebackers and outside linebackers coaches in 2026. While there will be changes made as to how the defense operates, Leonhard emphasized that the current version of the Bills are well-equipped to handle the switch.
"I think there is a level of versatility in there that is exciting to think about," Leonhard said about Buffalo's roster. "I am big on flexibility and being able to play to your best players and force offenses to try to find your issues and to have to deal with their own problems, not always being reactive."
Building an "aggressive" identity
Over the last two seasons, Leonhard learned under highly-respected Broncos defensive coordinator Vance Joseph. Joseph also runs a 3-4 defense. One of the staples of Denver's defense is sending five or more pass rushers at the opposing team's quarterback.
Since 2023, Joseph's first season in Denver, the Broncos blitz at the fourth-highest rate in the league (35.9 percent of plays). By comparison, the Bills rank 29th in blitz rate (22.9 percent) during that span.
Leonhard wants that aggressiveness to carry over to Buffalo.
"We're going to be an attacking defense up front and in the back end. We're going to attack the football. The biggest stat in football is turnovers, so we're going to be aggressive, we're going to fly around, we're going to communicate, we're going to play well together, but we're going to cause issues for offense, and we're going to force them to react to us," he explained.
A lack of a consistent pass rush was a sticking point for the last several seasons in Buffalo. The Bills ranked 19th in sacks over the last two years. While an improved pass rush is at the forefront of Leonhard's mind, he believes a successful unit is one that evolves week to week based on the opponent.
"We're going to be aggressive, we're not going to be reckless," Leonhard said. "There's a right and a wrong way in my opinion on how to attack quarterbacks in the NFL and it changes a little bit week to week based on their skill set …You have to try to change the comfort level of that quarterback, you got to be able to speed him up, you got to be able to slow him down."
One of Leonhard's other keys to a successful pass rush unit is developing a defense that stops the run on early downs to force teams into clear passing situations.
"You have to be able to control the tempo of a game," he shared. "The number one way to control the tempo of a game is stopping the run. To force them into situations where you're in an advantageous position as a defense, so a firm believer in stopping the run to make teams predictable."
Praise for current players and "earning respect"
When the Bills come back to One Bills Drive in the spring for the start of offseason workouts, Leonhard's priority is working to earn each player's respect and trust.
"We don't deserve their respect right away, you got to go earn it, and you've got to be consistent in the communication and consistent in how you approach your relationships," Leonhard said.
Many of the individual position groups on defense will have new positions coaches as well. Leonhard shared that he's bringing in assistants who also adhere to that mentality.
"As a player, I prided myself — I went from team to team a lot, went into a lot of different locker rooms — like 'How can I earn the trust and respect of this group quickly?' That was always my goal going in, that will be my goal as a coach and we'll challenge all of our coaches to have that mindset," Leonhard detailed.
While Leonhard is just getting started on breaking down film of each current Bills player on defense, he's already eyeing players to start building his scheme around, one of which includes top cornerback Christian Benford. Leonhard called Benford a "very talented player."
"I'm really excited to deep dive into the personnel, into the skill sets to create the best package for him. Not quite there yet. I'd love to give you a little bit deeper answer, but I have a tremendous amount of respect for the way he plays, the passion he plays with, the physicality, the energy," he said.
In 2025, Benford sometimes traveled with an opposing team's No. 1 receiver. Leonhard added that "it's something that we will consider as we go on" for Benford in 2026.
During his press conference, Leonhard repeatedly mentioned building his scheme around "known commodities" already on the roster.
"[Benford] is going to be a big leader for this defense and we're going to create the scheme around players like that," he said.
The new DC also praised the growth that safety Cole Bishop showed in his second season.
"I was a very big fan of Cole coming out of college. The versatility that he has, he's kind of a jack of all trades. He's physical. He can play out in space. He can cover. He kind of is the type of safety I tried to be myself," Leonhard shared. "You're starting to see those flashes show up more and more as I expected through the evaluation process."
Setting a vision for 2026
While Leonhard was plenty complimentary of Buffalo's existing personnel, he also emphasized that different types and styles of players are needed throughout the draft and free agency. The DC sat down with Bills general manager Brandon Beane and the scouting department during the week, outlining his plan to reshape the defense.
"A lot of big conversations with the scouting staff, with Brandon, and just what my vision is and how I think we're going to be there," he said.
During that meeting, Leonhard expressed that he understands it will be a transition for the scouting department as it works to identify possible fits.
"Trying to communicate as clearly as I could the things that I look for, the things that I value, the things that are kind of no-goes for me. I had a really good opportunity yesterday to just kind of throw a lot of things out there and get questions and try to bounce it as many places as we could, just to create as much clarity for that scouting staff," he added.
Bills head coach Joe Brady said Leonhard is a coach he has been "following for years" and he's excited to bring someone in who is as passionate about the game as he is. Leonhard praised Brady for his energy and direction for the team.
"He's very passionate about this place and you don't have to talk to him very long for that to come across," Leonhard said of Brady. "Then, just the communication, the openness that he's had with me on what he's trying to do, how he's trying to build this right, the people he's trying to get in the building, the culture of the team."
Leonhard is also looking forward to calling plays for the first time as an NFL coach. He has play-calling experience from his time at the University of Wisconsin, but he is eager to begin that role in the pros.
"The other exciting piece about talking with Joe Brady is the autonomy he's giving to me. Get the right people in the building as far as coaches and let's create a defense that we can all be proud of," he said. "Let's create a defense that the NFL doesn't want to play against."
