Oklahoma football coach Bob Stoops announced his retirement Wednesday after 18 seasons at the school.
Stoops is expected to address the team Wednesday.
“After 18 years at the University of Oklahoma, I've decided to step down as the head football coach," Stoops said in a statement. "I understand there has been some speculation about my health. My health was not the deciding factor in this decision and I've had no incidents that would prevent me from coaching. I feel the timing is perfect to hand over the reins. The program is in tremendous shape. We have outstanding players and coaches and are poised to make another run at a Big 12 and national championship."
Stoops, 56, compiled a 190-48 record during his career which included one national championship and 10 Big 12 titles. He is the school's all-time winningest coach, passing both Barry Switzer and Bud Wilkinson, who each won three national titles during their careers in Norman.
Offensive coordinator Lincoln Riley was named as his replacement. Riley was hired two years ago and oversaw an offense led by Heisman finalist Baker Mayfield.
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Stoops was hired in 1999 after serving as defensive coordinator at Florida under Steve Spurrier. He was previously an assistant at Kansas State with Bill Snyder and at his alma mater Iowa working for college coach Hayden Fry
Oklahoma had won just 12 games in three seasons with John Blake as coach before Stoops arrived. The Sooners went 7-5 in his first season and played in the Independence Bowl. That success set the stage for a 13-0 run to a national championship in 2000 that culminated in a 13-2 defeat of Florida State in the Orange Bowl.
Stoops would lead his team to three more BCS title games, losing to LSU, Southern California and Florida. That last of those losses was in 2008. The Sooners made the College Football Playoff in 2015 and fell to Clemson in the semifinals.
"It was with sadness that I learned of the decision of Coach Bob Stoops to step down as head football coach at Oklahoma," Oklahoma president David Boren said. "Coach Stoops has made a critically important and lasting contribution to the OU football program. He has led to its restoration as one of the top programs in the nation. His success has helped provide the momentum for major new facilities like the improvements and expansion of the football stadium. Because of his unquestioned personal integrity and high standards, he is one of the most admired college football coaches in America.
The list of Stoops' accomplishments includes coaching Heisman Trophy winners Jason White and Sam Bradford and several All-Americans, notably Roy Williams, Adrian Peterson, Trent Williams and Gerald McCoy.
He won more games in his first 18 seasons than any other college coach. Among the successes was an 11-7 record against rival Texas and a 14-4 mark against Oklahoma State.
The Sooners were particularly difficult to beat in Norman. Stoops was 101-9 at Gaylord Memorial Stadium, including a school-record 39-game home winning streak.
“I'm especially thankful for being able to coach so many talented young men over my 18 years here," Stoops said. "It has been so rewarding to see these players come to OU and mature over a four or five-year career, and not just on the field. To play a small part in their growth is what I will always cherish the most.
"None of my success would have happened without the best fans in the country. I can't tell you how much I appreciated the 110 consecutive home sellouts. The passion of our fan base is unmatched, and their support has played a huge role in not only home games, but road games and all 18 of our bowl games, as well."
His departure creates some uncertainty for one of the nation's top programs that was again expected to contend for a national championship this season.
Riley interviewed with Houston last winter and recently signed an extension with the school. He, like Stoops and Switzer, will assume the job having only served as a coordinator.
While that model work in both occasions, it did not work for two of Switzer's successors - Gary Gibbs and Blake - before Stoops arrived.
"I'm sincerely honored to be given this opportunity to be the head football coach at the University of Oklahoma," Riley said. "I want to thank Coach Stoops for bringing me here two years ago and making me part of the Sooner family. He is one of the greatest coaches in the history of the game, at any level. I'm absolutely thankful for our friendship and for the mentorship he has provided."
Stoops leaves a coaching tree of former assistants that includes Mike Leach, Kevin Sumlin, Kevin Wilson, Bo Pelini and Chuck Long.