Don Nelson, second winningest coach in NBA history, dies at 86 - espn.com

Don Nelson, the second-winningest coach in NBA history, died Sunday at age 86, his family announced, saying he passed peacefully surrounded by loved ones.
Across 31 seasons as an NBA head coach with the Milwaukee Bucks, Golden State Warriors (two stints), New York Knicks and Dallas Mavericks, Nelson compiled a regular-season record of 1,335-1,063 and made 18 playoff appearances, going 75-91 in the postseason.
He retired as the winningest coach in league history, a record surpassed by the San Antonio Spurs' Gregg Popovich in March 2022.
As a player, Nelson won five NBA titles across 11 seasons with the Boston Celtics, who retired his No. 19 jersey in 1978; he played 14 NBA seasons overall and was inducted into the Naismith Memorial Basketball Hall of Fame.
He began coaching with Milwaukee as an assistant in 1976-77 and was promoted to head coach just 15 games in after Larry Costello was fired, later adding general manager duties.
Nelson pioneered an unorthodox style dubbed "Nellie Ball," using smaller, athletic players and a fast pace to create mismatches, an approach epitomized by Golden State's early-1990s "Run TMC" trio of Tim Hardaway, Mitch Richmond and Chris Mullin; Warriors coach Steve Kerr called him "a true innovator" whose influence is still felt in the modern game.