Passing charts

I created passing-lane charts that trace the path of assists from the passer to the point where the scorer made the catch (the bright dot) to highlight passing tendencies and look for potentially useful defensive strategies. These are the passing-lane charts for 15 stars of the 2019 playoffs.

One thing that stood out was the big empty space on the right side of James Harden’s chart. On both his lobs and his kick-outs he prefers to pass from his left side to his right — zipping around an array of left-handed hook-, sling-, and slip-passes — because he is less fluid and less accurate passing in the other direction. During their two matchups with Harden during the 2018-19 regular season, the Milwaukee Bucks devised a defensive scheme meant to exploit these weaknesses and downplay Harden’s strengths.

In an effort to find other new ways to visualize passing tendencies, I borrowed the concept of a sonar chart from the world of soccer analytics. Sonar charts show how often players like to pass the ball in each direction.

My version of the pass sonar chart includes six passing locations: from the paint, from the top of the key (inside the 3-point line), from outside the 3-point line on the left, from outside the 3-point line on the right, from between the paint and arc on the left (under the FT line), and from between the paint and the arc on the right. For each passing location there is a set of four bars which indicate how often the player passed to each of four 3-point shot zones when setting up a teammate for a catch-and-shoot 3PA: to the left and right corners and to the left and right sides above the break.

Aside from showing the frequency of passes to and from each combination of court locations, there is a second layer of information to be found on these charts. The color of the bars at each passing location indicates what fraction of the resulting catch-and-shoot 3-pointers were wide open. Bright red bars mean that many (40%) of the 3PA created from that spot were wide open, whereas white bars mean that none of those attempts were wide open. This gives us a sense of the quality of shots that the player is able to create with his passes.

I also created something I called a triple-threat chart which indicates players’ dribble-pass-shoot tendencies by court location. As a proof of concept, I re-watched Game 6 of the 2019 Western Conference semifinals and logged every touch that was made in the frontcourt. In each instance, I jotted down where the player was standing when he caught the ball and what happened next: a dribble, a pass, or a shot. I recorded 107 front-court touches for the Warriors.

But how could we use a triple-threat chart like this in practice? Well, I think they could be pretty useful for understanding tendencies of individual players. As a defender, you could look up where on the court your opponent tends to catch the ball and what he prefers to do once he gets the ball in a variety of locations.

Check out more useful projects.

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