Boston Celtics enter another season with high roster turnover

Brad Stevens is entering his fifth year as the head coach of the Boston Celtics. He’ll have a number of new faces to incorporate into the upcoming campaign. In fact, eight of the sixteen players currently under contract with the Celtics for next year haven’t played a single game with the team. Six of them haven’t even have played a game in the NBA.

If that seems like a high turnover rate for a team that just went to the Conference Finals, it’s because it is. It’s uncommon to see a successful team undergo such a drastic roster overhaul, but such roster turnover is nothing new for Stevens. In his time with the team, including the players with assumed, guaranteed money coming their way next year, Boston has employed 51 different players (52 if you count Kadeem Allen’s two-way contract). That’s roughly a tenth of the league*, which is utterly absurd.

*Technically it’s a bit less than one tenth since there is also turnover in the player pool that this estimate doesn’t account for, but at any point in time, fifty players is just over ten percent of active roster spots.

Of those 51 players, sixty percent participated in just one (or part of one) season with the team. The average number of games played by Celtics under Stevens is 48.5 per season—a mark that represents just a tad over half a year, and fewer games than newly acquired All-Star Gordon Hayward played with Stevens in their two years together at Butler University.

Things get even more striking if you look across all four years of the Stevens era. During that span, players that signed with Boston averaged 78.8 games with the team. That means from 2013-2017, the average Celtic didn’t even play in one season’s worth of games.

To say the change in player personnel in Boston has come in waves during Stevens’s tenure would be an understatement, and yet the team has gotten better every single year. That’s a testament to him as a coach and the system he is building. Boston’s improvement under Stevens is also a case study in the importance of alignment between a front office and coaching staff.

Stevens has, in the past, mentioned how difficult it can be to deal with constant roster flux, but his coaching style actually fits fairly well with his rapidly changing environment. Stevens loves to experiment, even doing so at the expense of regular-season victories at times.

By bringing in a rotating cast of prospects, castoffs, and reclamation projects, President of Basketball Operations Danny Ainge gives Stevens all the resources his basketball laboratory could ever need. The Stevens era has been a collaboration between Stevens and Ainge in an effort to try out new combinations of players until they find something that really works, and it’s been wildly successful thus far.

Obviously there is a balance that must be preserved between stability and experimentation. Maintaining the team’s culture in the face of so much change is a challenging task for Stevens. At some point he’ll want to develop what he’s created in Boston and not just constantly recreate it with different parts.

Ainge is tasked with operating from a different perspective. If he sees an opportunity to upgrade his roster, it’s his job to take it. He can do so with confidence, given Stevens’s ability to develop talent despite a general lack of stability (from a player personnel standpoint—otherwise Boston is a very stable organization).

Such a setup can make life hectic, particularly for Stevens. But it’s working, and it’s a firm affirmation of the separation of coaching and front-office work—a lesson that might be instructive for teams like the Clippers or Pistons, both of which turned over general manager duties to their head coaches, with limited success at best.

Ainge and Stevens, on the other hand, have found a bit of magic in their respective and intentionally distinct roles. They’ll be hoping to keep it going in the upcoming year. Not everyone they bring in will be successful. For every Jae Crowder there are three or four Luigi Datomes or Vitor Faveranis. That’s all part of the plan though.

If you place enough bets, eventually some will start to pay off. At least that’s the theory here. In time, the Celtics are hoping they’ll be able to stand pat, but they’re not quite there yet. Until they are, Stevens will have to keep a seat open at the end of his bench for whomever comes through the revolving door. He’s done so masterfully thus far.