Don Nelson, the second-winningest coach in NBA history and a five-time championship winner as a player with the Boston Celtics, passed away on Sunday at the age of 86. His family confirmed his death in a statement but did not disclose the location or the cause. Throughout his final week, friends and family surrounded him with love, reminiscing about their cherished memories together. Known for his innovative point forward system and fast-paced offense, Nelson coached three different franchises - Milwaukee, Dallas, and Golden State - and served as general manager for all of them. He was a three-time Coach of the Year and led his teams to the playoffs 18 times in 31 seasons, though he never won a title with any team other than the Celtics. Nelson's coaching career began after retiring as a player, when he joined Milwaukee as an assistant coach. He went on to coach the Bucks for 11 seasons starting in 1976 and won seven straight division titles. In his second season with Milwaukee, the team overcame a 29-point fourth quarter deficit to beat Atlanta in regulation, a testament to Nelson's unconventional and speed-focused style of play. This style was most evident during his tenure with Golden State in the "Run TMC" era featuring Tim Hardaway, Mitch Richmond, and Chris Mullin. In between stints with Golden State, Nelson coached in New York for a season before being fired, then spent eight seasons coaching the Dallas Mavericks, taking time off to recuperate from prostate cancer surgery. His son, Donnie, joined him as an assistant coach with the Mavericks in 1998 and later became general manager, staying with the organization until 2021. Together, they convinced young German star Dirk Nowitzki to join the Mavericks instead of playing in Europe. Nelson also developed Steve Nash into one of the NBA's top point guards before Nash won back-to-back MVP awards with the Phoenix Suns. Current Warriors coach Steve Kerr described Nelson as a true innovator whose influence on the game is still felt today, while Stephen Curry, whom Nelson mentored in his final season as a coach, credited him for challenging him and shaping his career. Davis Nowitzki's teammate on the "We Believe" Warriors that upset Dallas in the 2007 playoffs, also paid tribute to Nelson.