Defensive versatility has been a common thread connecting the Boston Celtics’ most prominent big men across the past half decade. Not so much in the sense that Boston bigs have been able to guard multiple positions, but rather most have had the capacity to serve as the anchor point in a variety of schemes, particularly defending pick-and-rolls.
The Celtics go-to approach during the Brad Stevens head coaching era was to switch the majority of actions on and off ball one through four. Centers were asked to play up to touch, and then handle the difficult assignment of guarding the ball and the roll man simultaneously as the ballhandler’s primary defender recovered from the screen.
Not every big man is capable of filling such a role. It requires quick feet, expert timing, and enough size to be disruptive. Similar traits are needed to execute the bevy of alternative pick-and-roll coverages that Boston turned to situationally throughout the year, including more conservative drop schemes, switching, and (pretty rarely) aggressive doubles. With one glaring, Enes Kanter-sized exception, the Celtics have prioritized identifying centers with the tools to handle both their base approach and a variety of variants.
Al Horford was the prototype in his first stint in Boston. Aron Baynes and Daniel Theis filled in admirably as lower cost, but effective options. Tristan Thompson was a theoretical fit, but proved to only be up to the effort of plying his versatility on occasion, an issue compounded by frequently being paired next to Theis, leaving ample confusion about exactly when players were supposed to switch, and limited athleticism to scramble to cover holes.
The Celtics have a new head coach in Ime Udoka, and it is unclear if he’ll share Stevens’ enthusiasm for schemes that require big men to guard multiple players at once, but if Stevens’ first moves as President of Basketball Operations are any indication, the organization seems committed to retaining players that can make such a scheme work.
Robert Williams III’s recent 4-year, $54 million extension stands out as a particularly intriguing commitment. The fourth-year big man has all the tools to be an impactful and versatile defender. He’s long and quick, with decent feel for how to defend in space.
Williams can handle most switches and pops off the ground in an instant.
He’s an explosive athlete with shot blocking ability to make him a menace protecting the rim as a help defender.
Williams isn’t perfect, and he’s far from a finished product. He can get lost at times, and occasionally overcommits to pursuing blocks in ways that compromise the defense. He’s not quite large enough to handle the most intimidating individual assignments on the block. But Boston brought back Horford to bang with post behemoths, and most of Williams’ other on-court deficiencies are the kind that can be worked out with enough seasoning over time. The biggest concern really comes down to his health.
Williams has been sidelined by a seemingly endless list of maladies in his time with the Celtics. He’s never cracked the 55-game mark in his career, and only averaged 18.9 minutes per game last year. Paying Williams at the level Boston has locked itself into won’t be a disaster if he can find a way to be more consistently available, but it would certainly qualify as a misallocation of resources if he’s missing a third of the season. However, the other side of that coin comes with quite a bit of upside.
Williams’ idealized outcome – a rangy, athletic, uber-disruptive defender who enables your team to implement any defensive scheme – is the most valuable defensive skillset in basketball. There’s a clear argument to be made that massive deterrents at the rim, a la Rudy Gobert, are more useful in the regular season, but when the playoffs arrive, versatility is king.
Williams doesn’t have the natural feel to be the very best of the best of his player archetype - think Draymond Green or Anthony Davis – but his physical gifts are significant enough that it’s not crazy to suggest that if he stays healthy, he might reach a cut just below.
An absolute ton of things need to go right for Williams to realize his full potential, starting with staying healthy. He’s got to getter significantly better in space and needs to be in the right places more consistently. Williams has shown some serious development, despite not having logged a ton of game action in his three-year career, and in that sense there is reason to believe he will continue to improve. If he does, Boston may look back at his extension as a steal.