Prior to joining ESPN Radio in January 1992, Davis was a radio commentator for almost 30 years, launching his career in 1963 at WEMJ in Laconia, New Hampshire. He also worked in Boston, where for 10 seasons he was the radio voice of Boston College football on a New England-wide network. His call of the famous Doug Flutie-to-Gerard Phelan touchdown pass in the Boston College v. Miami game in 1984 is among the favorites of Boston area sports fans.
The Duke became a cultural icon when he was with The Tony Kornheiser Show between January 5, 1998 and March 26, 2004. When Davis reported the sports updates, the host, Tony Kornheiser, often interrupted Davis' reports with his own comments. At first Davis was shocked and not amused. Later they developed a very good chemistry that Davis started to add humorous comments within his report to amuse (or annoy) Kornheiser. The way Davis and Kornheiser talking back and forth prompted Kornheiser to say that The Duke was the glue of the show.