When it comes time for the NBA’s annual Summer League competition in Las Vegas, most of the basketball world’s attention is laser-focused on the players. Fans, media members and teams themselves want to see how players like Paolo Banchero and Chet Holmgren will fare in their first-ever action against professional competition, what James Wiseman looks like in his long-awaited return from injury and which rising second- (or third-) year players can prove themselves Too Good For Summer League.²⁶

But of course, players are not the only ones testing their skills or being evaluated at summer league. Most of the NBA’s 30 teams will elevate at least one coach into a new role as well. For those coaches, summer league is a rare opportunity for them to get head-coaching reps before actually becoming a head coach.

Some coaches look forward to it so much, they practically bowl over their bosses trying to get the chance. “To be honest, I asked Chauncey [Billups] if I could coach the team and he said yes,” Portland Trail Blazers summer league coach Steve Hetzel told reporters, when asked how he got the nod. “I beat everyone into his office. I was in at 5:30.”

That experience can pay off. Orlando Magic head coach Jamahl Mosley, who has more summer league coaching experience than almost anyone in the NBA,²⁷ noted that those few weeks leading the summer league squad provided him with invaluable experience to lean on later in his career.

“You get to master your craft and understand the aspects of the game that you might not necessarily see early on just working guys out on the floor,” Mosley said. “The real, game-time, understanding offense, understanding defense, understanding different scenarios. Putting together a practice. How does it flow? What are you doing? What are you trying to accomplish? What is your messaging? All of those things play a major part into how it transfers over to the game.”

Prior to landing the post in Orlando, Mosley interviewed for several other head-coaching gigs, and felt he could cite his summer league experience when asked specific questions about what he would do if he got the top job.

“So, in interviews, absolutely you are able to [say], ‘Oh, I would do this with our practice time.’ Or, ‘What would a day off look like?’ ‘What are you doing if somebody misses the bus?’ All of those questions that you could hit, you can answer them because you’ve been in those shoes,” Mosley said.

While Mosley has already taken the next step in his coaching career, there are others coming behind him looking to make a similar move up the ranks. It’s worth asking, then, if coaching a team in summer league actually leads to head-coaching opportunities in the future. Just how many of the league’s current coaches had prior experience in summer league before being hired to their current posts? How many coaches with summer league head-coaching experience have gone on and gotten a head-coaching job at some level, and how many are still waiting for their first opportunity?

FiveThirtyEight was able to acquire a surprisingly-hard-to-track-down²⁸ list of Las Vegas Summer League (LVSL) coaches dating back to the summer of 2015. During that time, 11 of the league’s 30 current head coaches coached an LVSL squad at least once.²⁹ Three of those 11 (Dwane Casey, Monty Williams and Nick Nurse) coached summer league only after being named head coach of their current teams, while three others (Mosley, Taylor Jenkins and Willie Green) coached both as NBA assistants and prior to their first season as a head coach. 

Now, there are a few caveats to consider with this data.

First, it only stretches back to 2015. For veteran coaches like Doc Rivers, Erik Spoelstra, Gregg Popovich, Rick Carlisle and Tom Thibodeau, we’d have to comb news reports from the 1990s and early 2000s to see if they had coached in any summer league prior to being named a head coach. Summer competitions were much less formal than the current version of LVSL, which makes finding complete data an extremely difficult proposition. Second, the data only includes LVSL coaches. There are still two other active summer league competitions (Salt Lake City Summer League and the California Classic) and until 2018, there was a summer league held in Orlando. The Las Vegas Summer League also did not include all 30 teams until that 2018 season. And there was no summer league competition in the summer of 2020, due to the COVID-19 pandemic.

So, ours is not a fully comprehensive list of potential future head coaches. Still, the rate of advancement for these summer league coaches seems fairly high. According to our list, there are 139 coaches who either coached or co-coached at least one LVSL team since 2015. Among that group, 18 were first-time summer league coaches this summer, which means they have not yet had the chance to advance to a head-coaching position. Meanwhile, 15 of them³⁰ coached in LVSL while they were the NBA team’s head coach and six coached in LVSL while they were the G League team’s head coach.

Of the remaining 104 coaches who have had a chance to be promoted from assistant coach to head coach after coaching an LVSL squad, 30 have gone on to be head coaches at some level:

Considering that teams currently employ an average of around five to seven named assistant coaches,³¹ the 28.9 percent rate of advancement to the head-coaching ranks since 2015 should be considered quite high. (And that’s before we consider that some of the current and former coaches could have also coached in one of the other summer leagues during this time period.) Obviously, there are not enough open jobs for 200-plus assistants to each get one.

The most questionable inclusions on our list of “eventual head coaches” are the interim coaches. However, we decided to include them in the table above because they became interim head coaches in the same season that they coached in LVSL. In 2018, Mike Miller coached the New York Knicks’ LVSL team, then was named interim coach when David Fizdale (who coached in LVSL in 2016, just prior to his first season as head coach of the Grizzlies) was fired during the 2018-19 season. Meanwhile, Jacque Vaughn coached the Summer Nets in both 2018 and 2019, then was named interim coach when Kenny Atkinson was fired during the 2019-20 campaign.³² Vaughn has since returned to the assistant coach’s chair under Nets head coach Steve Nash, who never coached summer league and had previously served only as a consultant with the Golden State Warriors (after a Hall-of-Fame playing career).

The group of 12 eventual NBA head coaches listed above includes current coaches Mosley (Magic), Green (Pelicans), Jenkins (Grizzlies), J.B. Bickerstaff (Cavaliers), Mark Daigneault (Thunder) and recent hires Darvin Ham (Lakers) and Will Hardy (Jazz). It also includes former coaches Walton, Atkinson, Lloyd Pierce, Nate Bjorkgren and Ryan Saunders. Of that group, only Daigneault and Saunders were hired to coach the same team they had previously coached in LVSL.

Among the nine eventual G League head coaches, five were hired for that role by the same organization they coached in LVSL³³, while four were hired away by other organizations.³⁴ Three of the nine (Darren Erman, Patrick Mutombo and Jama Mahlalela) have since returned to the NBA level as assistants — all with different organizations than those they coached either in LVSL or the G League. In addition, two of the G League head coaches entrusted with coaching the LVSL team later went on to become NBA assistants with those same franchises.³⁵

There is some debate about whether moving from an NBA assistant to a G League head coach (or vice versa) represents a step forward or backward in a coach’s career. One coaching source indicated that it would likely depend on the coach’s background. Coaches who come from an analytics or player-development background may be eager to coach in the G League so they can show off their X’s and O’s chops and facility with in-game adjustments, for example. Others would rather remain at the higher level of competition. Still others may prefer operating as a head coach to being an assistant, feeling it gives them a leg up in interviews.

Finally, it’s notable that seven of the 30 LVSL coaches who eventually moved on to top jobs did so for teams outside of the NBA. Becky Hammon, who interviewed for several NBA head-coaching opportunities, now coaches the WNBA’s Las Vegas Aces; Robert Pack coaches REG of Basketball Africa League; Matt Brase was recently hired to coach Pallacanestro Varese of Italy’s Serie A; and Juwan Howard (Michigan), Mark Madsen (Utah Valley), Micah Shrewsberry (Penn State) and Walter McCarty (Evansville) all coach or coached at the NCAA level.³⁶

Obviously, not every summer league coach will go on to nab a top job later in their careers. One of Mosley’s assistants, Jesse Mermuys, has coached in LVSL and elsewhere several times, but has yet to become an NBA head coach. Mosley told FiveThirtyEight that it will happen for Mermuys eventually, but Mermuys — who said he has asked each of the head coaches he’s worked with if he could lead the summer league team — appears to have other motivations.

“The reason why I always ask and want to do it is because I love it,” Mermuys said. “I enjoy it immensely. It’s a great experience.”

CORRECTION (July 18, 2022, 1:10 p.m.): A previous version of this article said Jesse Mermuys has yet to become a head coach. He has yet to become an NBA head coach, but was named the head coach of the D League Raptors 905 prior to our sample years of LVSL coaching data.