San Antonio Spurs coach Gregg Popovich and player Tony Parker. (David Santiago / AP)

This year's NBA Finals have gotten much attention for the entertaining match-up between two of the most powerful Big 3s in the league--Tim Duncan, Tony Parker and Manu Ginobili of the San Antonio Spurs and LeBron James, Chris Bosh and Dwayne Wade of the Miami Heat.

But it's also been a match-up between two of the longest-serving coaches in the league. Gregg "Pop" Popovich, who has coached the San Antonio Spurs for 17 consecutive seasons, and Erik Spoelstra, who has coached Miami Heat since 2008, are the longest and third-longest tenured leaders in the NBA.

It should tell us something about the NBA that a baby-faced 42-year-old who's in just his fifth season is the third longest-serving coach in the league. Since this year's season ended, a record 12 coaches--nearly half of whom made the playoffs this year--have been fired. Is it just a coincidence that the two teams with the best records also have such long-serving coaches? Or does it say something about the role continuity plays at the top?

Some say it's just a fluke year. Several of the moves come in light of ownership or front office changes or filling interim spots with permanent replacements. And there's not necessarily evidence of a trend: The average number of coaching changes per year is reportedly 6.5, and there were just three changes last year.

But Popovich and Spoelstra also have used their positions to speak out on this year's coaching carousel. In a media conference call last Friday, Popovich spoke about what he sees as the impatience of many owners who don't get the difficulty of building a winning team and called "continuity" one of his keys to success. "As you think about it, it seems like it would apply no matter what your business is," Popovich said. If a good team is in place, "you can deal with adversity and you cannot get too pumped up about success. ... But the change, change, change, change, change thing doesn't really work. You can see that in a lot of organizations."

Spoelstra concurred. "[For] true success in the NBA, you must have consistency of culture. When you see that type of turnover over and over and over, it's impossible to create any kind of sustainable consistent culture."

So who's right? The NBA, like most professional sports, has certainly become a journeyman's game, both for players and their coaches. The draft, team trades, and the free agent culture all conspire to create an environment that views people as interchangeable parts.

But just because it's a game of professionals doesn't mean anyone can necessarily work anywhere. Switching coaches may offer some instant success, but in a world where contracts are in the multi-millions, it's also obscenely expensive to cancel contracts, recruit new coaches, and then, of course, recruit new players who will fit in the new regime.

The coaching carousel also could result in worse performance. While the NBA might prove different results, a study by researchers at the University of Colorado, Boulder and Loyola University Chicago is worth bearing in mind. The researchers looked at the performance of college football teams that replaced their coaches over a 13-year period. For those teams that were already performing poorly, the study found that replacing coaches, by and large, had little effect. And those with "middling records"--something any of the NBA teams who made it to the playoffs and fired their coach should at least be able to claim--replacing the coach actually resulted in worse performance in subsequent years than comparable teams that decided to keep their guy on board.

Finally, the coaching turnover at the top of the NBA seems to ignore the potential effect on players who, obviously, like stability too. Some of those giants on the court, it's worth remembering, are just 19 when they enter the league. No matter how much of a professional or star they may be, they surely stand to improve from an ongoing relationship with their coach.

Take it from Pop, who, in his fifth NBA finals, is not only the longest-serving active coach in the NBA, but in all major professional sports. Continuity, he has said, "breeds trust, it breeds camaraderie, it breeds a feeling of responsibility that each member holds towards the other." That's not something you can build in two years.

Jena McGregor is a columnist for On Leadership.

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LeBron silences critics--for now

The coaching carousel in college football

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