BallR: Interactive NBA Shot Charts with R and Shiny

By Todd Schneider

The NBA’s Stats API provides data for every single shot attempted during an NBA game since 1996, including location coordinates on the court. I built a tool called BallR, using R’s Shiny framework, to explore NBA shot data at the player-level.

BallR lets you select a player and season, then creates a customizable chart that shows shot patterns across the court. Additionally, it calculates aggregate statistics like field goal percentage and points per shot attempt, and compares the selected player to league averages at different areas of the court.

Analyze your favorite players in the app below:

Enable javascript or click through from RSS to use the interactive BallR app

Run the App Locally

It’s very easy to run the app on your own computer, all you have to do is paste the following lines into an R console:

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packages = c(“shiny”, “ggplot2”, “hexbin”, “dplyr”, “httr”, “jsonlite”)
install.packages(packages, repos = “a href="https://cran.rstudio.com/">https://cran.rstudio.com/a>”)
library(shiny)
runGitHub(“ballr”, “toddwschneider”)

Chart Types

BallR lets you choose from 3 primary chart types: hexagonal, scatter, and heat map. You can toggle between them using the radio buttons in the app’s sidebar.

Hexagonal

Hexagonal charts, popularized by Kirk Goldsberry at Grantland, group shots into hexagonal regions, then calculate aggregate statistics within each hexagon. Hexagon sizes and opacities are proportional to the number of shots taken within each hexagon, while the color scale represents a metric of your choice, which can be one of:

• FG%
• FG% vs. league average
• Points per shot

For example, here’s Stephen Curry’s FG% relative to the league average within each region of the court during the 2015–16 season:

The chart confirms the obvious: Stephen Curry is a great shooter. His 3-point field goal percentage is more than 11 percentage points above the league average, and he also scores more efficiently than average when closer to the basket.

Compare to another all-time great, Kobe Bryant, who has been shooting poorly this …read more

Source:: r-bloggers.com