Basketball Hall of Famer Don Nelson, the NBA coaching icon who won five titles with the Celtics and 1,335 games as a coach, has died at 86.

Basketball Hall of Famer Don Nelson has died at 86, closing the book on one of the most unusual and influential careers the NBA has ever seen.

Nelson’s family announced his death Sunday, saying the former Boston Celtics champion and legendary NBA coach died peacefully surrounded by loved ones.

Few people ever attacked basketball from as many angles as Nelson did.

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He was a champion. A record-setting coach. An innovator. And, at times, one of the most unconventional minds the league had to deal with.

Long before “small ball” became part of everyday NBA vocabulary, Nelson was willing to throw away traditional positional thinking and force opponents to adjust to him.

His basketball story started as a player in 1962 with the Chicago Zephyrs before stops with the Los Angeles Lakers and, eventually, the Celtics.

Boston became home.

Nelson joined the Celtics in 1965 and won five NBA championships during his 11 seasons with the organization. He played alongside some of the greatest names in basketball history and became such an important part of the franchise that Boston eventually retired his No. 19.

Then came the second act.

And somehow, it became just as memorable.

Nelson moved almost immediately into coaching after retiring as a player in 1976, joining the Milwaukee Bucks before taking over as head coach during that same season.

What followed was a coaching career that stretched across more than three decades and multiple franchises, including Milwaukee, the Golden State Warriors, New York Knicks and Dallas Mavericks.

Nelson won NBA Coach of the Year three times, taking the honor in 1983, 1985 and 1992.

But his legacy goes well beyond trophies.

“Nellie Ball” became synonymous with unconventional lineups, offensive creativity and the willingness to use players in ways other coaches wouldn’t. Nelson often valued skill, shooting and versatility over traditional size, helping lay the groundwork for the positionless style that eventually reshaped the modern NBA.

His second run with Golden State produced one of the league’s great postseason shocks when the eighth-seeded Warriors knocked off the 67-win Dallas Mavericks in the first round of the 2007 NBA Playoffs.

When Nelson finished coaching in 2010, he held the NBA record with 1,335 regular-season victories.

He never won an NBA championship as a head coach, an ironic footnote for someone who won five rings as a player, but his impact on coaching was undeniable.

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The NBA recognized Nelson among its 10 greatest coaches during the league’s 50th anniversary celebration in 1996. He was later inducted into the Naismith Memorial Basketball Hall of Fame and received the Chuck Daly Lifetime Achievement Award in 2025.

Don Nelson didn’t just spend his life in basketball.

He helped change the way the sport was played.