Throughout the season’s twists and turns, the continued evolution of Robert Williams has been a common thread for the Celtics. While he isn’t the only reason Boston’s defense has been so impressive (Al Horford and Marcus Smart deserve their flowers, too!), Williams and his skillset are something that cannot be replicated by anyone else on the Celtics roster, or arguably anyone else in the league. In an era where otherworldly athleticism separates the good from the elite, Robert Williams is in the rarest of air based on his physical gifts alone. Add in a sprinkle of court vision and a dash of improved conditioning, and we’ve started to see Robert Williams really starting to reach his potential.