In 31 seasons as an NBA head coach with the Milwaukee Bucks, Golden State Warriors (twice), New York Knicks and Dallas Mavericks, Nelson finished with a regular-season record of 1,335-1,063. He retired with the most coaching wins ever, a mark that was broken by the San Antonio Spurs' Gregg Popovich in March 2022. Nelson made 18 playoff appearances as a coach, finishing with a 75-91 postseason record. As a player, Nelson won five NBA titles in 11 seasons with the
Boston Celtics, who retired his No. 19 jersey in 1978. Overall, he played 14 seasons in the NBA. Immediately following his playing career, Nelson joined the
Milwaukee Bucks as an assistant coach for the 1976-77 season. Just 15 games into that season, he was promoted to head coach after Larry Costello was fired.
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