Don Nelson spent much of his coaching career looking like a man who had misunderstood how basketball was supposed to work. Turns out basketball had misunderstood Don Nelson. Nelson, the Hall of Fame coach, five-time NBA champion as a player and one of the sport's great tactical eccentrics, died Sunday at 86. He leaves behind 1,335 regular-season coaching victories, second only to Gregg Popovich. But counting wins is probably the least interesting way to explain Nellie. Nelson coached the Bucks, Warriors, Knicks and Mavericks across 31 seasons and spent much of that time committing acts of basketball heresy. Go smaller. Play faster. Let forwards handle the ball. Drag big men away from the basket. Stop worrying about what position somebody is supposed to play and start worrying about what they can actually do. Today we call this modern basketball. Back then it was called: "What the hell is Nellie doing?" Nelson helped popularize the point forward, using players such as Marques Johnson and Paul Pressey to initiate offense rather than automatically handing the job to a traditional point guard. It was classic Nellie: if the conventional matchup didn't suit him, he'd simply invent another one. He never won an NBA championship as a coach. That fact feels increasingly irrelevant. He won five as a player with Bill Russell's Celtics, then spent his second basketball life trying to make the game considerably less predictable. Milwaukee won seven consecutive division titles under him. Dallas went from NBA furniture to a contender, with Nelson playing a central role in bringing Dirk Nowitzki to Texas. And then came the masterpiece. In 2007, Nelson's eighth-seeded Warriors faced a 67-win Dallas Mavericks team in the first round of the playoffs. Dallas was the No. 1 seed. Golden State had barely got through the door. Naturally, Nellie's Warriors won. "We Believe" became one of the NBA's great underdog runs, and Nelson eliminated the franchise he'd previously helped construct. If Hollywood wrote it, somebody would have sent the script back for being a little obvious. But Nelson's real legacy is everywhere now. Watch a modern NBA game. Centers shoot threes. Forwards run offenses. Coaches hunt mismatches relentlessly. Traditional positions have blurred into suggestions. Teams would rather create space than preserve some ancient idea of what a power forward is supposed to look like. Nellie Ball didn't conquer the NBA by winning the final argument. It conquered the NBA by becoming the argument. There was something fitting about Nelson himself, too. Basketball's great unconventional thinker eventually retired to Hawaii, where he grew coffee, played poker and became an enthusiastic advocate for marijuana. Phil Jackson got Zen Buddhism. Nellie got Maui. Of course he did. Don Nelson never coached an NBA champion. He did something rarer. He coached basketball long enough for basketball to catch up with him.