Bill Kollar enters his fourth season as defensive line coach for the Denver Broncos in 2018. He was hired by the club on Jan. 26, 2015.

Bill Kollar enters his fourth season as defensive line coach for the Denver Broncos in 2018. He was hired by the club on Jan. 26, 2015.

Kollar owns 34 years of coaching experience, including the last 28 seasons instructing defensive linemen at the NFL level. Before coming to Denver in 2015, he coached the defensive line for Houston (2009-14), Buffalo (2006-08), St. Louis (2001-05) and Atlanta (1990-2000).

In 2017, the Broncos improved from 28th in run defense to fifth despite a large turnover along the defensive line and mainstay Derek Wolfe being limited to just 11 games due to injury. Defensive ends Adam Gotsis (41 tackles) and Shelby Harris (5.5 sacks) had breakthrough seasons for the Broncos while free-agent defensive lineman Zach Kerr became a regular in the rotation.

Denver’s defensive line in 2016 overcame the loss of Malik Jackson (free agency) and Vance Walker (injured reserve) to help the Broncos finish the season fourth in total defense (316.1 ypg) and first in yards per play allowed (4.7). Wolfe had a career season in 2016, leading all NFL 3-4 defensive ends with 18 quarterback knockdowns despite playing just 14 games.

In his first season with the Broncos, Kollar led a defensive line that accounted for 18 of the team’s league-best 52 sacks. Five different defensive linemen posted multiple quarterback takedowns in 2015 and the unit batted down 11 passes at the line of scrimmage.

Wolfe and Jackson combined with nose tackle Sylvester Williams to start 43-of-48 possible games for the Super Bowl-champion Broncos while helping Denver finish first in the NFL in total defense (283.1 ypg), including a No. 1 ranking against the pass (199.6 ypg) and a No. 3 ranking against the run (83.6 ypg).

Before arriving in Denver, Kollar spent six years with Houston, including his first five years with the franchise as assistant head coach/defensive line. During his tenure with the Texans, the team ranked eighth in the NFL in total defense (329.4 ypg) and third in the league in opponent third-down percentage (35.9).

The five best run defenses in franchise history came during Kollar’s tenure with Houston, including back-to-back seasons (2011-12) in which the team held opponents to an average of less than 100 yards per game.

Kollar’s unit adjusted to the defense’s transition to a 3-4 scheme in 2011 under Houston Defensive Coordinator Wade Phillips. In addition to posting the third-largest defensive turnaround (-91.2 ypg) in NFL history in 2011, the Texans posted back-to-back seasons with a team-record 44 sacks in 2011 and 2012 to rank fifth in the league during that two-year stretch.

Defensive ends Mario Williams, Antonio Smith and J.J. Watt combined for five Pro Bowls playing for Kollar in Houston. Watt, who was named NFL Defensive Player of the Year by the Associated Press following the 2012 and 2014 seasons, led the league with 51 sacks during his four seasons under Kollar and became the first player in league history to post multiple campaigns with 20 or more sacks.

Kollar spent three years in Buffalo (2006-08), where he coached future All-Pro defensive tackle Kyle Williams and two-time Pro Bowl defensive end Aaron Schobel. Williams started 43-of-48 games to begin his NFL career under Kollar while Schobel was selected to play in consecutive Pro Bowls beginning in 2006 when he posted a career-high 14 sacks to rank second in the AFC.

Prior to his three-year stint with Buffalo, he spent five seasons coaching the defensive line in St. Louis. Defensive end Leonard Little ranked fifth in the NFL with 55.5 sacks during that span and was named to the Pro Bowl in 2003. Kollar’s defensive line was instrumental in the Rams’ 2001 Super Bowl run as the club ranked third in the NFL in rush defense (85.9 ypg) while tying for the seventh-most sacks (45) in the league.

Kollar spent more than a decade (1990-2000) coaching the defensive line for the Falcons, highlighted by an NFC Championship in 1998 and an appearance in Super Bowl XXXIII against Denver. Pro Football Hall of Fame defensive end Chris Doleman played two seasons (1994-95) for Kollar and totaled 16 sacks for the Falcons, including nine quarterback takedowns in 1995 to earn his seventh career Pro Bowl selection.

A defensive lineman for eight seasons with Cincinnati (1974-76) and Tampa Bay (1977-81) after being selected by the Bengals in the first round (23rd overall) of the 1974 NFL Draft, Kollar began his coaching career as a defensive assistant/special teams with the Buccaneers in 1984.

Kollar spent a year as a graduate assistant at the University of Illinois in 1985 before being promoted to coach the defensive line and special teams for the Illini from 1986-87. He coached the same position for Purdue University from 1988-89 before beginning his NFL career with the Falcons in 1990.

An All-American defensive lineman at Montana State University, Kollar went on to earn Most Valuable Player honors at the 1974 Senior Bowl and was inducted into the Senior Bowl Hall of Fame in 2014.

Kollar and his wife, Jan, have two sons, Chad and Clint. He was born on Nov. 27, 1952, in Warren, Ohio.

PRO BOWL PLAYERS COACHED (6): DE Chris Doleman (1995),DE Leonard Little (2003),DE Aaron Schobel (2006-07), DE Antonio Smith (2011), DE J.J. Watt (2012-14), DE Mario Williams (2009). *as primary position coach