Robert Williams is heading into what will be a critical offseason in his development process as he tries to elevate from bit player to a rotational regular.
And Celtics fans will be happy to know that the 2018 first-round draft pick has judiciously narrowed his focus on what he needs to improve over the next four months.
“I have to work on everything. There’s no limit. Everything.”
And as for what he felt he did well in his rookie year that...