In Teachey, North Carolina, Carr was the first African-American member of Wallace-Rose Hill High School's basketball team.

[5] The 1977 NBA Playoffs marked Carr's first postseason appearance, though Detroit, then in the Western Conference, were eliminated in the first round by the Golden State Warriors.

Carr was instrumental in leading the Celtics' defense past the favored Philadelphia 76ers in the 1981 Eastern Conference Finals, on the way to Boston's 14th NBA championship.

Carr is well known for the steal and dunk he made in overtime of Game 4 of the 1984 NBA Finals versus the Lakers in Los Angeles, which sealed the victory for Boston, and eventually won another title for them.

[citation needed] He was replaced at the end of season by Pitino, who was unable to restore the team to the glory of Carr's playing days.