Doing some research on schools, parks, churches, etc. where courts commonly are implies the number of courts here may be way too low. I assume this was a model trained by manually curated examples, so I wonder if a class of examples was missing from the training data.
I randomly thought of one in my city and went to look for it. It was missing, at 28.5860615, -81.3010721 or at least the court doesn't come up if you type the ZIP code there into the search box.
The labels come from OSM so it was probably done by somebody manually looking over Bing's aerial photography and manually tracing what they can see. The iD editor uses Bing not Google.
