To kick-start our individual team breakdown, it seems best to examine the team that led the Optimal Team Net Rating analysis: The Spurs.
We’ll begin by examining a chart that studies their Net Rating when their Offensive eFG% is above 50%, when their Defensive eFG% is below 50%, and when both statements are true.
What this means is that the Spurs are more dominant when they are defending efficiently than when they are shooting efficiently; however, they are the best in the league when doing both.
The first question, therefore, is why are the Spurs very good when maintaining a team average Offensive eFG% or Defensive eFG%, but more elite than any other team when doing both? The first answer was partially addressed in the previous post, but essentially, the Spurs only achieve their Optimal Team Net Rating 18% of the time. Due to the small sample size of games, though, if this solution is viewed as absolute it creates too much statistical noise. Consequently, other rationale must exist.
The first is presented in an article written on December 10, 2015 by Neil Greenberg at the Washington Post. In said article, Greenberg posits Lamarcus Aldridge’s post-up efficiency is a small reason; yet, the main reason he contends, is this is the best Spurs defense in recent memory. While that may explain the Spurs dominance when defending, this article has two problems: first, Greenberg’s thesis ignores the Spurs startlingly high Offensive eFG% (detailed below); and second, it does not explain the utter dominance when Spurs are both offensively and defensively efficient.
Thus, the reasoning this author suggests deals with how the Spurs are playing efficiently on offense. On net, the Spurs currently have the second highest Offensive eFG% in the NBA. With that said, they have fourth lowest “Three Point Attempt Rate” (the percentage of field goal attempts taken from the three point line) in the NBA and the third lowest three-point attempts per game for the franchise in the last ten years. Due to how eFG% is calculated – it ways the value of a three-point shot higher than a two-point shot – this seems contradictory. Yet, this assumption could not be further from the truth.
Figure 2 via Statmuse
The second reason boils down to a strategy utilized by the 2009-10 Boston Celtics – who averaged a top-5 eFG% while attempting only the 16th most three-point attempts per game – and the 2008-09 Los Angeles Lakers, who averaged eerily similar stats to the aforementioned Celtics team.
So what is this strategy? Effectively it revolves around having a few key pieces. First, big men who are threatening post-players that also excel in the passing game (Lamarcus Aldridge, Pao Gasol, and Kevin Garnett), a wing who is a very efficient mid-range scorer (Kawhi Leonard, Kobe Bryant, and Paul Pierce), and elite three point shooters (the Spurs retained three of their five best three point shooters from 2014 in Tony Parker, Danny Green, and Matt Bonner; the Lakers had Lamar Odom, Shannon Brown, Trevor Ariza, and Derek Fisher; and the Celtics had perhaps the best three-point shooter of all time in Ray Allen).
The way this offense works is relatively simple, but takes significant amounts of talent to be effective. The big men will frequently attempt post-up opportunities to draw the defense in, the mid-range shooter will work his hardest to create scoring opportunities, and the three-point shooters sit at the three-point line. Opposing teams, realizing a 40% three point shooter is more deadly than a 50% midrange or post-up scorer, will stick to the three point line.
Thus, certain things are needed. The post-up player has two responsibilities: force the defense to close in resulting in open lanes for the midrange shooter. Moreover, if he is doubled, he needs to be able to pass to the available three point shooter. This is an area where Lamarcus Aldridge, Tim Duncan, and Boris Diaw all excel.
It is crucial for the midrange shooter to score with high efficiency (Kawhai Leonard shoots a 56.4% eFG%, Paul Pierce shot at 53.5%, and Kobe shot at 50.2%). Additionally, they must create shots in the midrange room the post-up player provides as well as serve as the primary scoring option for the team.
Finally, the three point shooters must remain efficient from three and make any open shots they are awarded from opposing teams sending extra defenders to the post and/or middle of circle.
Consequently, the system’s cruel precision leads to efficient offense. Analytics, on the other hand, are not ignored but weighed less significantly than for a team like the Warriors or Rockets. This, combined with Neil Greenberg’s analysis of the Spurs stifling defense, means when San Antonio’s system works it is amongst the best in the NBA.