Sometimes when dealing with probabilities, things don’t always work out the way you might expect. My favorite example of this is the Monty Hall problem. The name comes from the game show Let’s Make a Deal, which was hosted by Monty Hall when it debuted in the 1960s. It’s still running today (with a different host), and the gameplay remains the same: A contestant chooses among three closed doors—behind one of which is a prize.