Nylon Calculus: Relating offensive style to offensive efficiency

One of my favorite tools to create over the past few seasons has been my offensive style charts. They are supposed to be a quick snapshot of each team’s offense, evaluated on four stylistic spectra, and separate for any judgements on good or bad. The stylistic traits are below.

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 of how quickly a team is working than traditional pace.

Shot selection continues to be the trickiest measure. For now we are using the simplistic MoreyBall percentage — 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 in a single number captures something about which areas of the floor each team is focused on attacking.

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.

Here’s what the top five offenses looked like last season.

The connection between shot selection and efficiency has the strongest relationship, which makes sense since shot selection has such a strong relationship with expected value and shot-making. However, the other three are somewhat strange.

We’re dealing with the small sample of a single season here, but it’s slightly strange to see essentially no connection between pace and efficiency. In addition, seeing negative correlations for both player and ball movement (less movement = more efficiency) seems counter-intuitive.

The Warriors are the standard-bearers for movement based-offense in the NBA, and they are also one of the best offenses we’ve ever seen. However, they’re likely skewing the numbers. Besides the Warriors, the five offenses that used the most player and ball movement last season (by combined percentile rank) were the 76ers, Nets, Suns, Spurs, and Hawks. The Spurs ranked seventh in offensive efficiency last season. The rest of that group ranked (22nd — Phoenix, 27th — Atlanta, 28th — Brooklyn, 30th — Philadelphia).

It’s possible that this is a blip of circumstance. Those four teams were also young, rebuilding (or pivoting in that direction), and short on elite offensive talent. Movement then becomes Plan A by default, because asking Trevor Booker or Alex Len to get buckets on their own probably isn’t going to raise the ceiling much.

Another interesting aspect is the relationship between the different stylistic elements and how they tend to cluster together. The table below shows those correlations, again with just last year’s data.

By far the strongest relationship is between player movement and ball movement — if you’re doing a lot of one, you’re probably doing a lot of the other as well. Interestingly, the two lowest correlations are between those two elements and shot selection — player movement and ball movement didn’t necessarily create better looks.

Here, I think it’s worth drawing a clear distinction between an offensive system and that player’s who are running it. No one really thinks that a team like the Nets could get the same result as the Warriors simply by running their system, but these numbers just emphasize how important talent is. Ball movement is most effective when the player on one end is a skilled passer and the player on the other is a good finisher. Ball movement works best when the player who is moving is a threat to score at multiple levels and thus occupies defensive attention.

The Warriors have become a historically good offense because they have a surplus of elite offensive players, and have been able to execute an extreme offensive system. The system, in and of itself, is just a means of raising the ceiling because of the way it fits that group. Asking the Clippers or Cavaliers to play the same way obviously wouldn’t produce the same results, not just because of a talent gap, but because it wouldn’t necessarily maximize the skills of each roster.

Next: Nylon Calculus -- Offseason movement and offensive styles

As we move towards the regular season and continue conversations about how each team should play and projections are assembled for how good each team could be, it’s probably worth remembering that talent is the place to start. Fit and style come second.