Nelson, who has been the coach of the Warriors for two separate stints (1988-1995, 2006-2010) has amassed a total of 1,335 wins over his years as a head coach, and scored more than 10,000 points as an NBA player.
Nelson was a three-time coach of the year, and leaves the game of basketball at the age of 70.
Now, the question some may ask, is "why now?"
For Nelson, this isn't what he wanted, according multiple media reports. Nelson originally pushed for a final season with the team, but the new ownership would like to move the Warriors in a new direction.
Nelson could find himself in the front office of a few different teams with openings—but would he want to?
At the age of 70, I'd be more inclined to take up golf and lick my wounds after a less than enjoyable last year in Golden State, which would lead to my "firing".
The Warriors struggled last season, even with rookie phenom Stephen Curry, to a record of 26-56.
For the Warriors, it's a move for the future, as Smart—whose only head coaching experience was in 2003 on an interim basis in Cleveland after the Cavaliers fired Jon Lucas—takes over the young Warriors squad.
He'll likely enter the Hall of Fame eventually as a Golden State Warriors coach, not as the coach of my beloved Bucks, with whom he won two Coach of the Year awards and that's OK with me. He's had a fantastic career, and he did the right thing for himself.
Looking toward the future with the Warriors and Smart, they have a chance to build to respectability again. Pieces like Curry, Monta Ellis, and Andris Biedrins are all capable players that the team can build around.
For Smart and the Warriors, the future has a pretty solid foundation, laid by Nelson.
Now, it's up to Smart and his staff to show they can take the opportunity and run with it in 2010-11.