Once again, I was spurred to throw together a data visualization while listening to a Bill Simmons podcast. This time, it was a Friday Rollin’ episode and Bill and Joe House were discussing substitution patterns that NBA coaches were using this year. They debated bringing the starters out all at the same time versus slowly rotating in the second unit. They debated how to get your stars the most rest while still maximizing their playing time. And they mentioned how Steph Curry was getting lots of opportunities to rest in 4th quarters this year thanks to big leads.
My mind was wandering over all the possibilities and wondering what all the different coaches in the league were actually doing. So I downloaded the data and I took a look. The result is nbarotations.info. Go ahead over there and read the explanation to get a feel for how to use it. Here's a screenshot showing the current average rotations for the Golden State Warriors this year:
There’s all kinds of things you can learn by exploring the data on the site. For example, most stars will get rest at the beginning of the second and fourth quarters. Some start just before the end of the first and others play to the end. Some older players sit for a short period in the middle of every quarter. Kevin Durant actually switched to this pattern in February of this year.
Other patterns show up as well. Injury riddled teams will have many players listed on their season average page. The Spurs experimented with their rotations throughout the season of their most recent championship, but were much more consistent this year.
I’m sure there are many more things to discover. Click around and explore.