“I did a bad job,” Brad Stevens said after his team lost four straight games to the Milwaukee Bucks and were eliminated from the playoffs. He called this season “the most trying” of his career. It was supposed to be the Braddest of Brad Stevens teams, a deep collection of talent that would go further than any of his try hard squads. They were favorites to represent the Eastern Conference in The Finals in large part due to their depth and talent level. Alas, that didn’t happen.

This season is a precarious inflection point for the franchise. The hard truth is that part of what makes Brad Stevens such a great coach in his first five seasons with the Celtics may not work if Danny Ainge puts together a dream team of stars this summer. Reminisce about those lovable Boston teams from a few years back and you recall names like Turner, Olynyk, and Crowder. Stevens masterfully maximized their talents and they moved on to sign lucrative contracts and are elsewhere, but have never really recaptured their mojo as a Celtic. That’s a credit to Stevens, but for the first time in his career, he did not meet expectations and they could potentially rise in July.

If Ainge can materialize the dream scenario of re-signing Kyrie Irving and dealing for Anthony Davis, it’s championship or bust. Regardless of who else remains on the roster, Irving and Davis are two of the top-20 players in the league. Supporting casts are retrofitted around these levels of cornerstones and more importantly, coaches gear offensive and defensive schemes to accentuate their strengths. This hasn’t always been Stevens’ M.O.

But there’s reason to believe that Stevens can cater to superstars. Irving turned in arguably his best offensive season of his career highlighted by an increase in efficiency and more effort on the defensive end, earning him 2nd Team All-NBA honors. However, there always seemed to be tension regarding Kyrie’s role. Irving was supposed to be one of those bright stars in the Celtics constellation, but everybody wanted to shine bright.

One of the biggest issues for Stevens might have been his egalitarian approach to the offense. Outside of Kyrie Irving taking on a little more responsibility as the team’s primary ball handler, the Celtics more or less shared the ball fairly evenly. Of the eight rotation players (not including big men Aron Baynes and Daniel Theis), six of them hovered around 18-22% in terms of usage rate; Irving had a 28.3 USG% and Marcus Smart was on the low end at 14.2%.

Celtics Usage Rate Player Regular Season USG% Playoffs USG% 2017-2018 Playoffs USG% Player Regular Season USG% Playoffs USG% 2017-2018 Playoffs USG% Kyrie Irving 28.3 29.1 N/A Jayson Tatum 21.6 21.1 23 Jaylen Brown 21.2 18.1 24 Marcus Morris 20.1 16.7 21.3 Al Horford 18.6 18.7 18.1 Gordon Hayward 18 14.4 N/A Terry Rozier 17.8 19.8 20.3 Marcus Smart 14.2 18.9 19.6

By comparison, consider other teams with singular talents like the Rockets or Bucks. For Houston, James Harden averages a 39.3% usage. Giannis Antetokounmpo dominates the ball at a 31.0% rate. Their rosters are built with teammates that are supposed to compliment their talents and sometimes, there can be conflicts. Philadelphia dealt with this type of drama just after trading for Jimmy Butler. Butler wanted to run more pick-and-roll in the offense. After being eliminated by the Warriors in six games this post-season, The Athletic’s Shams Charania reported turmoil between Chris Paul, James Harden, and Mike D’Antoni about the Rockets’ offensive style and ball movement.

During Terry Rozier’s whirlwind tour through the ESPN car wash, he revealed that Irving would often freelance outside of Boston’s system and that made it difficult to play off of his unpredictability. To some extent, that’s on Rozier and his teammates to adjust to the most talented player on their team; on the other hand, it obviously created friction in a locker room that was relatively drama-free sans Irving.

On the positive side, there’s always the magical run of Isaiah Thomas. Thomas was a legitimate MVP candidate that year and the best example of Stevens’ ability to get the best out of his players. But with all due respect to IT, that season felt more like catching lightning in a 5’11 bottle rather than the end product of calculated team building. And with all due respect to the members of that team, there weren’t a lot of potential superstars on that roster.

Regardless of what happens this summer, Stevens will have his hands full next season. The NBA is a stars league. Even if Boston doesn’t cash in their chips and decides to more or less run it back, there are still three players auditioning for breakout roles next year. If he’s not dealing with already established talents like Irving and/or Davis, he’ll be tasked with getting Jayson Tatum and Jaylen Brown over the next developmental hump and building on Gordon Hayward’s progress.

It’s possible that his all-for-one, one-for-all approach might work with a different cast of musketeers, but it’s difficult to consider last season anything but an abject failure. To his credit, Stevens often fell on his own sword, taking blame for not putting players in the right position to win or failing to manage timeouts and runs. No one can doubt Stevens’ basketball mind, but his greatest challenge will be more personal rather than about personnel.

The greatest in the profession have all had to deal with the egos of the best to ever play the game. Sometimes, it seems easier with players like Tim Duncan, Manu Ginobili, and Tony Parker. On the other hand, 90% of the job could be making sure Kobe Bryant and Shaq don’t kill each other. It’s not just about doling out field goal attempts or playmaking responsibilities. Stevens will have to manage and motivate personalities.

In an interview with the Boston Globe’s Adam Himmelsbach, former assistant coach Micah Shrewsberry said:

“We were never able to really galvanize ourselves as a team for a long stretch,” he said. “We would do it in short spurts, but then just wouldn’t carry that over. That’ll be something that eats at us as coaches and players.”

Shrewsberry talks about stealing schematic pieces from Milwaukee and Toronto and Golden State, but at its core, the issues that plagued Boston last year were more so in the locker room than on the floor. Stevens is fond of saying that he categorizes players into three buckets: ball handlers, wings, and bigs. Next season, he may need to narrow that down even further to two: stars and role players.