Matt Parker is a “standup mathematician.” In this entertaining video, he demonstrates a 1960s plastic toy that plays the game of Nim against a human opponent. Interestingly, Dr. Nim is an ingenious mechanism that uses plastic levers to control the number of marbles it chooses to drop. If you go first, Dr. Nim will always win. In the video, Matt shows you how to play and win Nim every time, including a cheat that lets you win even if you go first.