After graduating from UW–Platteville, at the age of 21, Davis took over as head coach in Milledgeville, Illinois. He attempted to mimic the martinet coaching style of his own college mentor, John Barth, but concluded that "You have to be yourself. What works for someone else isn't going to work for you just because it worked for him."
Davis then became head coach at Portage High School in Portage, Wisconsin. While there, he faced a dilemma in allotting playing time to his players, most of whom he believed were good enough to warrant it. Davis awarded playing time to all deserving players, which gave rise to his philosophy of constantly pressing and rotating players in an effort to wear down the opposing team.
Davis began his coaching career at Lafayette College in 1971. During his six-year tenure at the school, he posted a 116-44 record, advancing to the NIT in 1972 and 1975. Future Maryland head coach Gary Williams, who had played as a point guard under Davis at Maryland, served as one of his assistants at Lafayette.
He would accept a position at Stanford University before taking over as the head coach at the University of Iowa in 1986. While at Iowa, he led the Hawkeyes to nine NCAA Tournaments, including a pair of Sweet Sixteen appearances as well as an Elite Eight. The Hawkeyes also made two NIT appearances. He is the winningest coach in the University of Iowa history.
His team was ranked number one during the 1986-87 season. The Hawkeyes won a school record thirty games before eventually being beaten in the Regional Final of the NCAA Tournament by UNLV 84-81. Following the 1998-99 season, Iowa chose not to renew Davis’ contract and he temporarily retired from coaching.
Davis was named Drake University's 23rd head basketball coach on April 22, 2003. In four short seasons, Davis re-energized a Bulldog program that had not had a winning season since the 1985-86 season. He led Drake to a 17-15 record; including winning the Big Four Series, Drake Regency Challenge, and Sun Bowl Tournament.
On March 21, 2007 Davis announced his retirement from college coaching. His son Keno Davis took over as head basketball coach at Drake University. Davis’ career included sixteen 20-win seasons, eighteen post season appearances, and he was named Associated Press National Coach of the Year in 1987. In 2008 he was inducted into the University of Iowa Athletics Hall of Fame for his success as a coach during his tenure there. He currently lives in the Iowa City area with his wife Shari.
Drake Bulldogs(Missouri Valley Conference) (2003–2007)
National champion Postseason invitational champion Conference regular season champion Conference regular season and conference tournament champion Division regular season champion Division regular season and conference tournament champion Conference tournament champion