Erik Spoelstra quietly made history last week. He didn’t see a reason for celebration.

Spoelstra is in his 17th season as coach of the Miami Heat, which is the third-longest uninterrupted tenure by one coach with one team in NBA history. Gregg Popovich is in his 29th year with San Antonio, and Jerry Sloan had a 23-year run in Utah.

For most coaches in today’s NBA, the idea of such a run may seem impossible.

Half of the league’s coaches — 15 of the 30 — are entering no more than their third year in their current job. There have been eight coaching changes in 2024 so far alone, and there’s still two more months for an owner or general manager to decide to add to that list.

“That’s a sobering reality of this profession,” Spoelstra said. “It bums me out when I hear that stat because there are a lot of really talented coaches that if they had the same type of structure and continuity and belief from (their teams) ... there could be a lot more coaches able to do what I’m able to do here.”

It’s no secret that the term “job security” doesn’t mean much in coaching, especially now.

The WNBA — coming off one of its most successful years ever in terms of attendance and attention — had 12 teams this season; seven of those teams currently do not have coaches. The Dallas Wings are about to hire their fourth coach in seven seasons. The Atlanta Dream made the playoffs; they let Tanisha Wright go anyway. The Indiana Fever, with Caitlin Clark coming off her record-setting rookie year, fired Christie Sides over the weekend after a 1-8 start was turned around into a playoff berth. And on Monday, the Connecticut Sun and coach Stephanie White parted ways after back-to-back trips to the WNBA semifinals.

The WNBA isn’t trying to emulate the NBA’s coaching carousel, but here we are.

“Leave it better than you found it,” Sides posted on social media after the Fever let her go.

The NBA still might be the gold standard when it comes to impatience with coaches, though. This past offseason saw some moves that, on paper, looked wild.

The Lakers hired JJ Redick away from ESPN; Redick’s only previous coaching job was leading fourth graders earlier this year. Phoenix parted with NBA champion Frank Vogel and replaced him with NBA champion Mike Budenholzer (whose ring came at the Suns’ expense in 2021). JB Bickerstaff became the first coach to take a Cleveland Cavaliers team that didn’t have LeBron James to the second round in more than 30 years and he, too, got fired.

Bickerstaff ended up with Detroit. The Pistons had fired Monty Williams after one season — with five years and something like $65 million left on his contract. Williams now will coach his sons at a high school in San Antonio.

“You just keep doing the job you’re supposed to do,” Bickerstaff said.

He could have added “for as long as you have it,” because in the NBA, who knows what’ll happen next.

Popovich fired Bob Hill as coach of the Spurs 18 games into the 1996-97 season and named himself coach. Tim Duncan arrived and changed the franchise’s fortunes a year later, but in this NBA era Popovich’s record in the completion of that first season — 17-47 — probably wouldn’t have given him a chance to keep the job.

The move, obviously, paid off. Popovich has more wins than anyone in NBA history. And, when counting moves involving interim coaches, the next coaching change in the league will be the 300th since Popovich began coaching the Spurs.

There have been 183 different coaches in the league since Popovich started, not including himself. Of those, 78 have coached multiple franchises in that span — Alvin Gentry, Larry Brown, Mike D’Antoni and Doc Rivers have coached in five different places over those years, and another nine coaches having worked for four different franchises in that time.

“You’re always striving to be the best that you can be,” said New Orleans coach Willie Green, who is entering Year 4 with the Pelicans and has been in his job longer than half the other coaches in the league have had their current gigs. “But you take these jobs, understanding that they don’t have a long shelf life.”

Popovich isn’t getting fired. Spoelstra is in Year 1 of an eight-year deal. Golden State’s Steve Kerr will decide when it’ll be his time to leave the Warriors. Joe Mazzulla surely has earned tons of security after leading Boston to an NBA title. Mark Daigneault has done an amazing job in building Oklahoma City. There are others who would surely be safe in their current job if things turn south, but probably not many.

“There’s been 14 jobs open just in the last two years alone,” said Spoelstra, part of a group in Miami — including team president Pat Riley — that is entering 30 years with the Heat. “In that regard, I think it’s really a sad state for coaching. Coaching staffs aren’t given enough of a time period to be able to develop a culture, develop the right habits, to go through the necessary adversity to get to that next level. I’m grateful we have that structure and stability here.”