If you read our 2013-14 preview for the Thunder, you might've noticed that I dumped in a quick two paragraphs on the Thunder's defense. To recap, they had the league's third best defensive efficiency last season, allowing 99.2 points per 100 possessions. OKC finished the regular season with a 9.2 adjusted point differential, one of the highest in league history. While they carry a roster loaded up with defenders ranging from capable to great, the reason for their success is due to their mobility and athleticism as a team.
How that translated on to the court was that Scott Brooks had his team defend the paint more conservatively, as opposed to tight on the ball on the perimeter. Players generally sagged off on outside shooters by a few steps more than we might see in other systems, and by collectively doing that, it would make it difficult for opposing players to get good shots at the rim. If the pass went to those outside shooters, then the Thunder took advantage of their mobility and athleticism to recover and close on the shooters to challenge shots.
This strategy prioritizes defending the paint first and shutting down dribble penetration. It will concede some open jumpers, but the Thunder bank on their players being able to at least contest those shots, if not stifle them altogether.
In this first play, the Suns run a pick-and-roll between Goran Dragic and Marcin Gortat. Dragic is immediately confronted by Kendrick Perkins and Kevin Durant cutting off any lane into the paint. As Gortat rolls to the rim, Ibaka rotates to cover him. This leaves the Suns' pick-and-roll with no shot at the rim, but Ibaka's check, Luis Scola, is open for a midrange jumper. As Scola takes his jumper, however, Ibaka recovers and uses his length to force Scola to try and lift his shot over Ibaka's contest. It doesn't work for Scola.
Here, the Thunder face Deron Williams coming off of a pair of screens. Like Perkins earlier, Ibaka is playing loosely on the pick-and-roll so as to cut off the lane to the paint. Williams chooses to pull up for the jumper, but Ibaka is even able to aggressively close and swat that shot.
In both plays, you'll notice how important Ibaka's length is. While you'll often see him rack up the blocks right at the rim, his raw length and athleticism makes him an extremely dangerous player in this scheme as he can contest outside shots with ease, even when his first priority is cutting off the paint.
Adding the Thunder's perimeter players to the mix is when this defense becomes even more difficult to solve. Durant used his long frame to help wall off the lane in the earlier Suns play and though he might not have been able to help if the Suns had spaced the floor better, he does a good job of cutting off the lane when he's in position to do so. More importantly, when opposing offenses kick it out to their shooters, he and the rest of the Thunder's perimeter players do a strong job of returning to their original checks. Thabo Sefolosha in particular is one of the league's better players at recovering after a help rotation, along with being one of the best on-ball perimeter defenders in the league.
In this play, you will see the Thunder cut off attempts to the rim multiple times. Ibaka stops DeMar DeRozan curling off of a screen, and then Ibaka and a recovering Perkins cut off Amir Johnson rolling off of a pick-and-roll. This second sequence ends with Sefolosha having rotated over to Ed Davis, and as the pass goes to an open DeRozan in the corner, Sefolosha recovers and forces him baseline where he knows he has help from Ibaka, who cuts of DeRozan. In the end, DeRozan bricks a contested fadeaway from the short corner late in the shot clock.
This time, the Lakers move the ball around the perimeter. Pay attention to how slack the Thunder tend to play the Lakers' perimeter players away from the ball, as they're clearly wary of Dwight Howard in the paint. Yet when a perimeter player catches the ball, the Thunder recover so that they're close enough to dissuade both dribble penetration or a three-point shot. The Lakers eventually do space the floor and give the ball to Dwight in the post, but Sefolosha helps out on the drive. The ball moves to Kobe Bryant, but Sefolosha recovers on to the dribble penetration and shuts it down. Kobe passes to a cutting Earl Clark, but Ibaka is ready for him quickly stuffs his shot.
This strategy is how the Thunder intend to set up their defense every time. The paint comes first, and the Thunder then rely on communication and elite level athleticism to close out on shooters.
The biggest problem that arises is when opposing teams can draw Kendrick Perkins out of the paint. Perkins ordinarily does a great job of shutting down dribble penetration, staying front of the ball handler, or challenging shots at the rim, even though he does not have the same shot blocking ability as Ibaka. However, Perkins' bulky frame and slower foot speed effects the defense when he is baited out of the paint on a pick-and-roll. His inability to retreat quickly leaves a noticeable void in the paint. Opposing teams have an easier time penetrating to the rim, particularly when using small ball lineups that already put an emphasis on spacing the floor. Mike Prada wrote a post a few months ago about the Thunder's struggles defending small ball lineups because of that very reason.
However, Perkins' tendency to overhelp out of the paint is an addressable problem. As Prada suggests, Perk playing more conservative defense (akin to what we saw from Ibaka in the earlier Nets video) would help, even if he lacks Ibaka's dominant length. Trading deep twos (which are exactly the type of shots you would like to lure an opposing team into taking) for layups is the fundamental principle that Scott Brooks' conservative defense revolves around, after all.
Given OKC's young roster, playing such conservative defense works extremely well. The Thunder have the athleticism to play a more aggressive style defense that we might see from the Heat or Bulls. However, more than a handful of Thunder players that struggle with the finer details of NBA defense, and those players do get caught out of position or missing rotations when OKC plays too aggressively for prolonged stretches. By using this conservative scheme, the style stays basic, keeps most of the action in front of the defenders, and then capitalizes on the collective athleticism. The Thunder maximize what get out of their players on defense, and this coming year we expect more of the same.