Davis accepted a basketball scholarship from the University of Maryland, to play under head coach Lefty Driesell.

He declared for the NBA draft after the season, finishing with an average of 12.2 points and 5.1 assists per game during his three-year stint in college.

On February 12, 1979, he signed as a free agent with the Indiana Pacers, to provide depth after Kevin Stacom was traded.

[3] In 1979, he signed with the Anchorage Northern Knights of the Continental Basketball Association, where he helped them win the league championship.

On December 2, 1980, Davis signed as a free agent with the NBA expansion team Dallas Mavericks, when the franchise was nearly two months into the 1980–81 season and became the starting point guard.

In the 1987–88 season, he was a part of a team that reached the Western Conference Finals only to lose to the eventual champion Los Angeles Lakers in seven games.

Davis was the radio analyst until the 2007–08 season, when he swapped positions with Mavericks TV commentator Bob Ortegel.

They later switched back to their original roles and Davis remained the color commentator on Mavericks' radio broadcasts.