Nylon Calculus: Revisiting offensive style for the 2016-17 season
By Ian Levy
On offense, every team is after the same thing — put the ball in the basket. What makes the game so beautiful is that there are infinite ways of accomplishing that goal and endless variations on strategy and approach that can be used to pursue it.
In general, basketball analytics spends a lot more times trying to answer questions of “what” and “good or bad” than of “how.” That’s why I have had so much fun over the past few years assembling offensive style charts. With just a few days left in the regular season, I’m happy to share this year’s versions, with a few small tweaks.
These charts are not meant to evaluate whether an offense is good or bad. They are designed to help illustrate how teams go about the goal of trying to put the ball in the basket. Each team’s offense is evaluated on four stylistic spectrums.
Ball movement is measured with the average touch time for each team, from the NBA’s player tracking statistics. A lower average touch time means the ball is moving from player to player more quickly.
Player movement is measured with a combination different NBA.com tracking statistics, and works out to average distance traveled per 24 seconds of offensive possession.
Pace is measured with the average length of an offensive possession from Inpredictable, a more accurate representation for how quickly a team is working than traditional pace.
Shot selection continues to be the trickiest measure. In the past I had used Seth Partnow’s XeFG% which estimates what a team’s effective field goal percentage should be given the location of their shots, the mix of catch-and-shoot and pull-ups, and how close the nearest defender was. However, those stats were built on the player tracking shot logs which stopped being publicly available on Jan. 25 of last season. This year I went with a more simplistic measure and used MoreyBall percentage — in this case the percentage of a team’s true shooting opportunities that came at the rim, from the free throw line, or on a 3-pointer. It’s a generalized measure but captures something about how much each team hews to the shots that are, on average, the most efficient.
On the graphs below you’ll see a line for each team’s offense. As the line moves away from the center of the graph on each axis you’re seeing more of that stylistic trait. For example, shot selection shows a (hypothetically) more efficient shot selection the further you are from center.
The Warriors and their offense have been the NBA’s shiny new plaything over the past few seasons and when it comes to these offensive style charts, they certainly stand out.
The Warriors’ offense is at the extreme on all four spectrums — with the fastest pace in the league, ranking in the 97th percentile in player and ball movement, and a shot selection in the 79th percentile in terms of generalized efficiency.
The Warriors’ offense has been so good over the past two years, and their style is so striking, that’s easy to fall into the trap of assuming that they represent some pure, idealized vision of efficiency. However, there isn’t necessarily a direct correlation between style and results. For example, compare the Warriors to the Rockets, how have the second-most efficient offense in the league this season.
The Rockets average just under a point less per 100 possessions than the Warriors. They are even more extreme with their shot selection and like, the Warriors, are among the fastest-paced teams in the league. However, Houston ranks below the 50th percentile in both ball and player movement.
The engine of Houston’s offense is James Harden and they achieve their efficiency by keeping the ball in his hands, letting him break the defense and make reads on the best scoring option. It’s a different formula but, with Harden’s brilliance and a deep roster of shooters around him, it achieves similar results.
We see a similar pattern — or lack thereof — if we expand and look at the five best offenses in the league this season.
The Nuggets play a style that’s fairly similar to the Rockets. Although, with Nikola Jokic as a somewhat more static offensive fulcrum, they utilize more player and ball movement. The Cavaliers and Raptors rely much more heavily on the talents of their isolation scorers — rankings towards the bottom of the league in movement and pace. They don’t necessarily need pace and movement to the same degree because Kyle Lowry, DeMar DeRozan, LeBron James, Kyrie Irving, and Kevin Love are so skilled at grinding out efficient shots in the halfcourt.
Looking at the five worst offenses in the league also emphasizes the separation between style and results.
The Hawks, Nets, and 76ers all play a style that’s fairly similar to the distinctive style of the Warriors — uptempo, lots of movement, lots of 3-pointers, shots at the rim, and free throws. Obviously, the difference in talent level leads to some very different results.
Below you can check out the charts for all teams this season.
There’s lots to dig into here — the evolution of the Spurs’ offense, which just two years ago was a stylistic copy of the Warriors, the overblown evolution of the Grizzlies’ offense, the “pace-and-space” approach of the Pacers which doesn’t appear to actually be using either element.
Next: What happens when teams start trapping James Harden in the playoffs?
Please peruse, enjoy, share. Let me know if you find anything interesting I’ve missed or haven’t covered.