As the Clippers were handed a decisive 26-point home loss by the Spurs Thursday night, TNT's Reggie Miller and Chris Webber referred to the Spurs' offense as a “machine.” Every player knows where he needs to be, what pass to make, and which open shot to take (yeah, a lot of times they have many in the same possession).
A lot of credit for the Spurs' offense is given to “best point guard in the NBA right now,” Tony Parker, who went for 31 points, 7 assists, and a game high +31 plus/minus on Thursday night. But the key to the machine is clicking on all cylinders: The Spurs' effective use of on- ball screens in the halfcourt.
Using the Vantage data set, we can see how the Spurs’ use of on-ball screens leads to "effective outcomes" (i.e., scores, assists, open shots, passes to open shots, passes to shooting fouls, and shooting fouls). On the flip side, we also see that when defending against on-ball screens, a more aggressive initial screen defense can limit the dribble penetration of the screen receiver as well as scoring opportunities from role players.
On-ball screens are a major part of the Spurs' production. To start, the screen quality of Spurs' on-ball screens is among the best in the NBA -- Spurs' on-ball screens make contact with or reroute defenders 50.75% of the time (2nd only to Detroit). Out of the 24.33% of Spurs' on-ball screens that lead to effective outcomes, nearly 15% of those plays are passes to missed open shots, which leads all NBA teams in the Vantage data set. But the Spurs are top in the league in offensive efficiency. These stats show how crucial it is for the Spurs' machine to be working together. The fact that the Spurs are missing a high percentage of open shots in screen situations and yet still are among the best in the league in scoring in these situations illustrates that their efficiency isn't driven by raw scoring prowess but rather by generating so many good looks that they more than make up for their misses.
Tony Parker’s use of on-ball screens aids him in his ability to facilitate the offense. Of the on-ball screens he receives, 81.88% involve not splitting the screen and not refusing the screen, another example of the structured nature of the San Antonio offense. Overall, Parker will pass coming off a no-split, on-ball screen nearly 75% of the time. Out of those screens, Parker generates an effective outcome (assist, crucial pass, pass to open shot, pass to shooting foul) 34.02% of the time. This suggests that a way to limit Parker’s ability to penetrate and find open shooters is to limit his actions when he comes off the screen. Pressuring Parker and forcing him to retreat (which our data set shows he is forced to do only about 8.24% of the time) would help in limiting his ability to feed the machine.
With 59.44% of all of Parker’s on-ball screens received coming from the high post or 2-point wings, an initial screen defense that hedges against on-ball screens may have the most success when defending these court locations. Sampling the entire data set, we can see that hard-show screen defenses lead to ineffective or nonsignificant outcomes 64.1% of the time, as opposed to soft-show and drop-zone defenses, which yield to ineffective or nonsignificant outcomes 61% and 57.39% of the time, respectively. Although hedging can be a more aggressive initial on-ball screen defense, especially against a quick player such as Parker, statistically it allows the fewest field goal attempts against and scores by a player the defender isn’t guarding. Although it may give up the fewest field goal attempts, it gives up the highest field goal percentage (44.96% compared to more frequently used initial screen defenses, playing behind or showing, which give up 38.91% and 34.31%, respectively). The reward with hedging, however, is that the recovery rates are a lot higher, as 70.9% of hedges lead to recovery on secondary screen defense (compared to 61.9% and 58% for drop zone and soft show, respectively). Thus, the hard hedge allows the defending guard to recover as the primary defender, which limits dribble penetration.
Ultimately, one way to stop the Spurs is to not allow all of the moving parts of the machine to function according to plan. Through Parker’s facilitation, which has been especially noticeable this season (6th in the league in assists), it has helped guys such as Matt Bonner and Kawhi Leonard gain All Star weekend recognition as the benefactors of the high-powered offense. Limiting the offense through aggressive screen defense puts more pressure on the ball-handler, while limiting role players’ presence in San Antonio’s offensive schemes.