The NBA is a player's league, where coaches are regularly fired only a few years after winning Coach of the Year honors or even a championship. In order to last for more than a couple years, you better be close to the greatest that there ever was.
Longevity is just one of many measures that point to the excellence of recently-retired coach Gregg Popovich. His 29 years and 2,291 wins at the helm of the Spurs puts him behind only Lenny Wilkens and Don Nelson in that category.
Coach Pop was by far the longest-tenured coach in the league when he finally decided to hand the reins over to Mitch Johnson on Friday. His resume speaks for himself. He's an icon that had wild success throughout multiple eras of Spurs basketball.
There's little doubt that Pop was the best coach of his generation. His three NBA Coach of the Year awards don't do him justice. He was way ahead of the curve on a number of trends, and he was largely considered the greatest tactician in the game for much of his tenure. But how does he fare all time among the best of the best?
All-time NBA head coach rankings

1. Gregg Popovich
Career Coaching record: 2291-1422 (.621 winning percentage)
Titles: 5
Pop is the LeBron James of coaches, who enjoyed had one of the greatest peaks of anyone who ever commanded the bench in the NBA.
What makes him the undeniable GOAT is that he was so good for so long.
It's hard to imagine any other coach making 22 consecutive playoff appearances for a single team, as he did from 1998 to 2019. His teams won 50 or more games for 18 straight years during that streak. He amassed 1,422 regular season wins during his career, which is an NBA record that will probably never be broken.
Popovich succeeded with a variety of talent throughout that time, successfully navigating from David Robinson, Tim Duncan, Kawhi Leonard, DeMar DeRozan, and Victor Wembayama. He got his teams to play selflessly, creating a beautiful style of basketball that has been replicated in playgrounds around the world.
Popovich had some good talent to work with. Tim Duncan won two MVPs during his time with the Spurs. But he never had a player like Michael Jordan, Kobe Bryant, Shaq, or Bill Russell. He won five rings anyway, convincing players like Manu Ginobili to sacrifice for the betterment of the team. Pop always found diamonds in the rough off the bench, getting those guys paid on other teams.
Popovich was a student of the game. He brought over the best European players and coaches, incorporating international tactics to the NBA. He recognized the value of corner 3's before anybody. He was way ahead in terms of strategic adjustments, allowing his teams to overperform relative to their talent level.
Pop was also a great mentor and person. Stories of his generosity are legendary. He served in the Air Force for five years and was politically active, even when speaking out was difficult.
Pop has helped foster the careers of so many other coaches throughout the league. Current coaches Ime Udoka, Steve Kerr, Doc Rivers, Will Hardy, and Quin Snyder all played with or worked under him with the Spurs. Erik Spoelstra and Jamahl Mosley worked under him with USA Basketball, where he won a Gold medal in 2020 as head coach. His legend lives on through the rest of the league.
MORE: Meet Mitch Johnson, new HC of the San Antonio Spurs
2. Phil Jackson
Career Coaching record: 1640-1155 (.704 winning percentage)
Titles: 11
It's pretty tough to argue with six consecutive titles and nine in 11 years. Jackson had three different three-peat runs between the Bulls and Lakers, dominating the 90's and early 2000's. He won another two with Kobe Bryant and Pau Gasol in 2009 and 2010.
Joe Mazzulla (.740) and David Adelman (undefeated in three games) are the only coaches with a better regular season winning percentage than Jackson's. Let's see them maintain that over 20 years, as Jackson did.
Jackson detractors will say that he was gifted with superstar players like Michael Jordan, Kobe Bryant, and Shaquille O'Neal. What they can't discredit is that he succeeded in managing those (and many other) big egos better than anyone.
The Zen Master's greatest gifts were empowering his brilliant long-time assistants Tex Winter and Johnny Bach, along with knowing how to motivate his stars. He wasn't necessarily the best tactician — he never embraced the value of 3-pointers and would willingly concede corner 3's. The game seemed to pass him by even more as an executive with the Knicks.
Despite his old school tactics, he got the absolute most of his teams from a chemistry standpoint, which is usually the most important thing when it comes to winning. And he won a lot.
3. Red Auerbach
Career Coaching record: 938-481 (.661 winning percentage)
Titles: 9
You have to be pretty darn good to have the Coach of the Year trophy named after you. Auerbach won the award only once. He made up for that slight with nine championships in 10 years, including eight in a row. Nobody was touching the Celtics with him at the helm.
Auerbach's greatness isn't in question, and he was the best when he retired. He's not quite at the top of this list now simply because of how Popovich outlasted him for nine years and Jackson won two more titles.

4. Pat Riley
Career Coaching record: 1210-694 (.636 winning percentage)
Titles: 5
Riley was a winner from the get go, leading the Lakers to their first of four championships under him in his first year as an NBA head coach. He pioneered the "Showtime" era of the team, forming wildly entertaining offenses with Magic Johnson and Kareem Abdul-Jabbar at the helm.
Riley showed that he was capable of coaching multiple different styles, grinding out more physical victories later with the Knicks. He got New York to the Finals only once, creating a fantastic rivalry with Jackson's Bulls during those years. He closed off his coaching career with a Heat title in 2006.
Riley has won Auerbach's trophy three times, which ties Popovich and Nelson for no. 1 all-time. He's the only coach to do it for three different teams.
What defines Riley is how he was one of the most creative motivators in coaching history. He once famously almost passed out after holding his head under a bucket of ice water in order to encourage his team to treat winning like it was their last breath.
5. Steve Kerr
Career Coaching record: 567-308 (.648 winning percentage)
Titles: 4
Kerr took over a good Warriors team from Mark Jackson and turned it into a dynasty, winning his first of four championships during his rookie year and making five consecutive Finals appearances. His .703 winning percentage in the playoffs is third all-time behind Mazzulla and Mark Daigneault.
Kerr has always been a top tactician. He saw the value of 3-point shooting and the potential of small ball units far before anyone else. Those trends have now been copied all over the league.
Kerr designed the perfect system around Steph Curry and Klay Thompson, freeing up his shooters to have the ultimate green light and fly off screens for each other.
He's also learned from the older generation, playing under both Popovich and Jackson and combining the best from both coaches into his own personal philosophies.
Kerr is the lowest on this list, but he's also the youngest. He still has plenty of years left to try and move up.
Honorable mention: Erik Spoelstra, Larry Brown, Chuck Daly, Red Holzman, K.C. Jones, Jack Ramsay, Jerry Sloan, Lenny Wilkens, Don Nelson