Sports are growing more international with respect to the athletes. Gregor Aisch, Kevin Quealy, and Rory Smith for The Upshot show by how much, with a focus on leagues in Europe and North America.
I like how: The dominant home country in each chart doubles as background and a layer; the tooltip shades the country you moused over while still showing the other countries; and the missing data and gaps are shown clearly but don’t obstruct the overall view.
