I stumbled upon a probability exercise when I had just built enough confidence with R scripting, and I was looking for “toy problems” to play with. It was a simple brain teaser, barely more complicated than the well-known coin toss. I could solve it with pen and paper, but I wanted to squeeze out of it as much as I could. My central thesis in this post is that, if we formulate our assumptions well, we can turn questions about probability into questions about data.