This experiment is seventy years old, and it was built out of relays before it was ever written as software.
This machine is a somewhat simplified model of a machine designed by D. W. Hagelbarger. It plays what is essentially the old game of matching pennies or "odds and evens." This game has been discussed from the game theoretic angle by von Neumann and Morgenstern, and from the psychological point of view by Edgar Allen Poe in the "The Purloined Letter." Oddly enough, the machine is aimed more nearly at Poe's method of play than von Neumann's.
That is the whole idea in one sentence. Game theory tells you the correct way to play matching pennies: flip a mental coin, be genuinely random, and no opponent can beat you over time. Poe's detective does something else entirely. He studies his opponent and guesses what sort of person would choose what. Shannon built the detective, because the detective wins. Not against an ideal player. Against an actual one.
