The first two years of Robert Williams III’s NBA career were always about what could be.
What would happen if Williams could manage more than 61 combined games across his first two seasons? What if he could avoid the foul trouble — over 4.0 per-36 minutes — that had kept him from earning more playing time in the games he was healthy enough to suit up for?
Everyone saw glimpses of what the hype was about. Length. Athleticism. Rim running. Rim protection. Boston hadn’t hit on many of its later picks. Could Williams, drafted 27th in 2018, join Jayson Tatum and Jaylen Brown as a legitimate building block of the Celtics' future?
Though possible, it’s all moot unless Williams provided the best ability any athlete can have: availability.
Well, in his third season, Williams appeared in 52 games, the most of his career. His minutes increased to a career-high 18.9 per game, resulting in his fouls per-36 minutes decreasing from well over four in his first two years combined to 3.8 in 2020-21.
The result was not a definitive answer on the type of player Williams will be throughout his career, just a much-needed reaffirmation that he continues to be on the right track.
“He’s getting a lot better. You see that,” Brad Stevens said of Williams back in March. “And he’s able to play a little bit longer stints than he has in the past because he plays really hard when he’s out there.”
Each member of Boston’s center rotation brought something different to the table. Tristan Thompson was a rugged interior force on both ends. Daniel Theis — when on the team — was a bit more of a floor spacer and ball mover.
Williams brought what neither could: hops that provided a vertical dimension to the Celtics’ pick-and-roll game, allowing them to punish more flat-footed bigs or evade lankier ones. He generated 1.23 points per possession as the roll man, top-20 among players with at least 60 possessions.
“It’s the best part about it,” Kemba Walker said of Williams’ leaping ability. “You just know if you put it up there, he’s going to go get it.”
The same athleticism Williams used to sky above the rim at the offensive end was also used to protect it at the defensive end. Always a quality shot blocker with over 3.0 per-36 minutes for his career, that trend continued in 2020-21 with 1.8 a game, which ranked No. 1 among players who earned fewer than 20 minutes a night.
He had multiple games with four blocks and one with five against Milwaukee. Williams blocked six shots against Brooklyn during the regular season and another nine (!!) in Game 1 of their first-round matchup.
In the play below, Jeff Green does everything right upon grabbing the offensive rebound, immediately going back up without bringing the ball down. But Williams is just that springy, and it impressed at least one All-Star on the other side.
“His timing is amazing,” former teammate Kyrie Irving said. “It’s great to see a big that’s active in our game, and he challenges you at the rim every single time.”
But maybe more important than the ability to get up for a block is knowing when to remain grounded, a challenge for Williams in his first two seasons.
A lower foul rate this past season was the result of his developed discipline that, for example, kept him in front of Landry Shamet instead of lunging at the sharpshooter before following him to the basket and then blocking his shot.
More playing time also allowed Williams to showcase his passing abilities, often making plays out of the short roll. That’s a necessary skill playing alongside Jayson Tatum and Jaylen Brown, two elite scorers who will be forced to give up the ball in the pick-and-roll with opponents daring the open man to make a play.
Williams carved up an LA Clippers team that opted for this defensive strategy, dishing out three of his four total assists in the fourth quarter to help bring the Celtics a victory.
All these skills came together in different ways throughout the season. Sometimes Williams found the bottom of the basket more than usual or crashed the glass more aggressively, or found teammates with passing at an above-average rate.
He had the aforementioned performances highlighted by his block totals. Williams also went for 14 points, 11 rebounds, and four assists in 22 minutes against the Pacers.
His best outing came in Houston, where he needed less than 26 minutes to drop 20 points, nine rebounds, eight assists, and two blocks. Williams became the 10th player in NBA history to record at least 16 points and 13 rebounds in a game while playing fewer than 20 minutes.
Per-36 minute potential materializing into tangible on-court production was a large reason Boston felt comfortable trading away Theis at the deadline. Williams had been groomed for two years. He was now ready for more, specifically the starting job.
In one sense, Williams lived up to what the Celtics thought of him. His numbers increased across 13 starts to 9.5 points, 8.3 rebounds, 3.1 assists, and 1.7 blocks per game.
But in another, injuries came into the equation late in the season, resulting in Williams missing 12 of Boston’s last 17 regular season games followed by an absence in Games 4 and 5 of their first-round loss to the Nets, thus creating concern about his ability to hold up as the long-term option at center.
With the return of Al Horford and a potential contract extension on the table, there’s no telling what the future holds for Williams, but he has made clear that the more run he gets, the better he’ll be. Boston got a greater taste of what that might look like this past season, and it was one of the few things they’re hoping carries over to the next one.
“Rob’s development since he got here has been really good. We continue to challenge him on staying locked in from game to game,” Jaylen Brown said. “The more he’s on the floor, the better he’s going to get. We’re looking forward to that.”