Vince Carter is currently in his 22nd NBA season, which is the longest career in NBA history. At 42-years-old, Carter has signaled that this will be his final year playing professional basketball.

Carter is an iconic player in NBA history. Widely known as one of the best dunkers to ever touch an NBA court, is it quite shocking that someone of that skill has lasted 21 years. Usually, players who rely heavily on their athleticism fade out of the league faster than those who rely on, let us say, shooting.

This is for obvious reasons, as you get older you start to lose the same juice you had in your legs that you had when you first came onto the scene.

So, what's so different about Vince Carter that has him playing across four different decades?

Well, let's just compare Carter's rookie season to his final NBA season. In Carter's rookie season, he only attempted 1.4 three-point attempts. In his final season with the Atlanta Hawks, Carter is averaging 3.8 attempts a game.

Carter developed a three-point shot throughout his career, one that has allowed him to stay in the league as long as he has. In fairness to Carter, this wasn't something he added just at the end of his career.

Unlike some players who don't expand their game outside of their freakish athletic ability,  Carter has always had a quite reliable jump shot to his game. If you take what many believe to be his prime years in the NBA where he was an all-star for eight straight seasons, Carter shot the ball from distance even more than he has in his last six seasons.

From 2000-2007, Carter shot 4.3 attempts from long distance and made them at a 37.9 percent clip. In his last six seasons, Carter is averaging .8 fewer attempts a game, at 3.5 attempts from deep.

So, has Carter really evolved his game? Sure, as he's gotten older and become an obviously worse basketball player he's taken on an off-ball role. Unlike earlier in his career, when he was the main ball-handler and scorer on his teams. His usage rate was above 20 percent in his first 16 seasons but has now fallen below 20 percent all of his last six seasons; getting as low as 14.7 percent.

But, as was pointed out earlier, Carter has always been able to shoot the ball from beyond the arc. Maybe, looking back on it, it shouldn't be as shocking Carter has lasted longer than other players who were known as freakish dunkers.

However, if it wasn't his game that really evolved, what was it or what has changed that has helped Carter play in the NBA longer than most rookie's ages?

The answer is his mentality.

Carter was never a locker room issue or a bad guy off the court. This positive about Carter has helped him change fluidly from diva superstar to veteran locker room presence.

Carter hasn't looked to sign with great teams to try and win titles. Would championship contender teams want the aging Carter? Has he been good enough the past few years to actually play on a good team?

Well, Carter never allowed that question to be answered. Instead, Carter has taken pride in joining young, developing teams. He's taken on the role of the veteran in the locker room and enjoys trying to help young players improve and learn the ins and outs of the NBA.

His mentality has changed from a player wanting to win a championship as a young superstar in this league to an aging vet who wants to help build a foundation and a culture among up and coming franchises.

However, don't let this fool you. Carter believes he can still play at an NBA level, or he wouldn't still be playing.

His mentality, though, is what separates him from other aging players who find themselves out the league.

Vince Carter isn't about ring-chasing; he's about setting a culture and living on through the younger players he's teaching.