Sports is a world of “what-could-have-been’s.” What could have been if only the Portland Trail Blazers had chosen Michael Jordan in the 1984 draft. What could have been if only the Oklahoma City Thunder had kept their core three of Russell Westbrook, James Harden, and Kevin Durant in 2012.

And one that will haunt Dallas Mavericks' fans to no end: what could have been if only they had kept Steve Nash and Dirk Nowitzki together in the early 2000's.

Nash was traded to the Mavericks in 1998 and spent six seasons in Dallas. There, he and Dirk Nowitzki quickly grew as one of the most feared pick-and-roll duos in the league. Both Nash and Nowitzki were players on the rise, and they propelled the Mavs to 53, 57, and 60 wins, respectively, from 2000-2003.

But those Mavs never quite hit their full potential. In the 2002-03 playoffs, they reached the Western Conference Finals, only to fall to the eventual-champion San Antonio Spurs. That was the farthest they were destined to go with their two stars. Nash and Nowitzki led the Mavs to four straight playoff berths, but would never taste the NBA Finals together. And after the 2003-04 season, Mavs owner Mark Cuban was getting restless.

Doctors close to him had told him that the 30-year-old Nash would break down sooner rather than later, and now was the time to move on. Cuban listened to their advice, and chose to invest money in younger players rather than giving Nash a large contract. He would build around budding star Dirk Nowitzki, and let Nash walk in free agency. When he was later asked about the worst move he had ever made as owner, he responded:

“Letting Steve Nash go. I learned an expensive lesson. It took me too many years to realize that for some GMs, their number-one job wasn’t winning a championship, it’s keeping their job. It’s easy to look back and see my mistakes today. I wish I would have been smart enough to know better back then. I loved taking risks to win. Unfortunately some of them were not as educated as they should have been.”

Nash would go on to sign with the Phoenix Suns, teaming up with coach Mike D’Antoni. Together, they revolutionized the NBA. Implementing a run-and-gun style of play, they unleashed a “seven seconds or less” offense that featured Nash as the general. It was a fast-paced attack that was efficient, exciting, and explosive. Nash would win two MVP awards in the process and would continue playing for another 10 years after he left Dallas. He was inducted into the Hall of Fame in 2018.

Nowitzki, meanwhile, would continue to grow as the Mavericks’ franchise player. He would finish his illustrious 20-year career with the Mavs, reaching the NBA Finals twice and winning the title in 2011.

But one will always wonder “what could have been” if only Mark Cuban had chosen not to let Nash walk in 2004. Nash, for one, believed he knew what would have happened.

In August 2019, 15 years after Nash fatefully left Dallas, he told D Magazine that he definitely thought they would have won a championship if Dirk and he had stayed together:

“Would we have won a championship? Of course. Why not? I mean, you never know. Keeping me in Dallas wouldn’t have really affected their salary cap situation. They still would have been able to bring in the other guys they brought in, for the most part. I think it would have been interesting.”

One can always dream. Nash's ability as a floor general in his prime. Nowitzki's ability as one of the best shooting big men in NBA history. If they only had more time, with the right pieces around them, they undoubtedly may have turned into something special.

Today, the Mavericks once again boast two international superstars on the rise. Luke Doncic and Kristaps Porzingis now breathe new life into Dallas. The young, exciting duo is reminiscent of another back in the early 2000's. While it's still too early to deem them the next Nash and Nowitzki, their surprisingly-strong start to the season has Dallas fans flashing back to an era in Mavs' history that could have been something more.

But one thing's for certain: this time around, you can bet that Mark Cuban will think twice before separating these two superstars on the rise.

Or else we'll always be wondering what could have been.