The Bulls have been the league's best defensive team since Chicago hired Tom Thibodeau before the 2011 season. But they've achieved that in a sort of counterintuitive way. The NBA is a pick-and-roll league, and you can feel Thibodeau's stress building when he starts talking about facing "50 or 60 or 70" pick-and-rolls in the same game, "and with so many variations." The pick-and-roll is a two-man play, generally involving a ball handler and a big guy setting a screen for that ball handler. Chicago has built its defense around an interesting principle: It wants one of the two guys directly involved in the pick-and-roll shooting at the end of it.