Even without Derrick Rose and Luol Deng, the Chicago Bulls have managed to hold their own with a 29-26 record—good for second in the Central Division. Much of this is due to Tom Thibodeau and the grinding, defensive-minded mentality he has instilled in his Chicago Bulls.
But as with any team, it all starts with the team's leaders taking on the personality of their coach.
In Chicago, Joakim Noah has completely adopted Thibodeau's style of play, anchoring one of the best defenses year after year. It's his leadership at the back end of the defense that allows the team as a whole to function so well.
This season is no different, with the Bulls' 97.8 defensive rating ranking second in the league, according to NBA.com. And since the departure of Deng—arguably the team's best perimeter defender—the team's defensive rating has managed to hold steady at 97.9.
This would seem to indicate that Chicago's defense is more a function of system than personnel. Since Thibodeau arrived, the Bulls have shuffled various perimeter players in and out of the door and have filled the bench with a ragtag crew of players. Yet through all of this, they have maintained their stellar defense.
And it's true, to a degree: Thibodeau's defensive system is one that has been copied throughout the league due to its continuous success—first when Thibodeau was the de facto defensive coordinator under Doc Rivers in Boston, and now at the helm in Chicago.
There is one underlying key to Thibodeau's defensive philosophy: Overload the strong side of the floor.
When the ball is on one side of the floor, help defenders are pushed all the way over into the paint, leaving weak-side shooters seemingly open. The idea is to only give up the longest possible pass—anything cross-court—while pressuring the ball and deterring penetration into the paint.
Thibodeau's defense actively takes advantage of the defensive three-second rule, which states that a defender cannot be further than arm's length from an offensive player and in the paint for more than three seconds.
Thibodeau's Bulls, therefore, do what's known as 2.9-ing: They'll hover in the paint for 2.9 seconds as a blockade, discouraging any ball-handler from driving into a cluster of defenders. Right as the three-second violation is about to get called, they'll scramble out.
It takes impressive discipline for weak-side defenders to execute this scheme. If a cross-court pass is made, it's easy to close out on defenders too hard, allowing an easy blow-by. It's even tougher on the bigs, having to patrol the entire paint as a last line of defense.
With Noah as its anchor, the Bulls defense makes it look easy. While he certainly receives much acclaim for his rim protection and his rebounding, it's often his work before a ball-handler even reaches the paint that sets the tone for a defensive possession.
Take this play against the Toronto Raptors, in which DeMar DeRozan eventually hoists up a contested three-pointer. Noah is nowhere near the final result of the possession, but it's his work away from the ball as a penetration deterrent that eventually forces DeRozan into a poor shot.
As the play initiates, John Salmons Iverson cuts to the opposite wing—a cut in which a wing player sprints across two screens from bigs on the elbows. On the catch, Noah notices that his defender, Mike Dunleavy, is trailing a bit far.
An adept Salmons would immediately catch and explode to the rim, with Dunleavy's momentum carrying him the wrong way.
Noah reads this possibility and drops off his man, Tyler Hansbrough. When Salmons turns, he's now staring at Noah's help with Dunleavy closing fast. This forces him to pull the ball out to the top of the key as the play develops further.
Next comes an on-ball screen, which Salmons rejects with a crossover and starts heading towards the paint. The moment Salmons gains an advantage, Noah pushes over towards the middle of the paint.
This immediately cuts off any further penetration towards the basket, and Salmons is either forced to pull up for a difficult shot with Dunleavy all over him or kick the ball out. He chooses the latter.
Now it's DeRozan's turn, facing shot-clock pressure and with the designed play completely blown up.
He starts to rock the ball back, sizing up the defender and looking for an angle to drive. But again, take a look at Noah. Instead of following Hansbrough all the way to the short corner, he elevates slightly.
Notice how he's feeling for Hansbrough with his right arm while keeping his eyes trained on DeRozan. Because he's a few steps higher, he's in a better position to help should DeRozan drive.
For DeRozan, he must now account for Noah: He knows any drive left will lead to an encounter with the big man, and his elevated position means its unlikely that he will be able to attack Noah without him in a proper guarding position.
Most NBA offenses rely on the pick-and-roll in some fashion. Combating it is one of the key missions of any defense, and Noah's versatility allow the Bulls to employ the most difficult, but effective, scheme.
The Bulls use what's known as a "drop." When the pick is set, the big drops well away from the action into full basket-protection mode.
Meanwhile, the guard defending the ball fights over top the screen. It's the big's responsibility to contain the ball-handler until the on-ball guard can get back into proper position. All the while, both defenders are coordinating to guard the roller, making sure he's not open for an easy drop-off pass.
The Bulls perfectly execute their pick-and-roll defense on this play, when Noah drops to the elbow after Jonas Valanciunas sets a pick for Kyle Lowry. D.J. Augustin, per Chicago's defensive rules, fights over the top.
What makes this a particularly difficult scheme is the pressure it puts on the defensive big. Not only does he have to corral the ball in a vast open space, but he also has to keep an eye on the roller. He's essentially guarding two players for multiple seconds until his guard can get back into the play.
The benefit of this style of defense is that it cuts off three-point shooters and essentially limits the play to a two-on-two situation. Guards are also tempted to pull up for mid-range shots when the big drops, which is arguably the worst shot type on the floor.
Here, Lowry probes looking for a lane. Noah, however, is often able to handle quicker guards due to his athleticism, and manages to keep Lowry at bay until Augustin recovers. He also cuts off any passing angle to the rolling Valanciunas.
Eventually Augustin recovers, and Lowry takes a difficult hook in the lane.
The Chicago Bulls' defense is built around the burden it places on its bigs. Noah, Taj Gibson and Carlos Boozer all bear a large burden, and it's their work around the paint that makes the perimeter players look good. But ultimately it comes down to Noah, who logs huge minutes while never relenting in his effort.
Quite simply, this type of defense is tiring and requires the primary big to wear multiple hats. Noah is so talented, however, that he makes it look easy.
But without him as the anchor, Chicago's defense would be nowhere near as effective.