How Claude Shannon used information theory to cheat at Vegas roulette

Claude Shannon is one of the great, heroic titans of the computer science revolution, a brilliant scientist and Feynman-grade eccentric whose accomplishments fill several excellent books.

One of my favorites is James Gleick's The Information: A History, A Theory, A Flood, which blew me away in 2011.

A new book, A Mind At Play: How Claude Shannon Invented the Information Age, also looks like a lively read. This excerpt in Nautilus describes how Ed Thorp, a grad student who'd written a paper on card-counting, was recruited by Shannon to help him build a cigarette-pack-sized computer that could be used to cheat at roulette, and how the two scientists and their wives traveled to Vegas to prove that it worked.

Picture a roulette wheel divided up into eight segments: By June 1961, Thorp and Shannon had a working version of a device that could determine which of those segments would end up holding the ball. As soon as they concluded that they had, in fact, found their edge, Shannon impressed upon Thorp the need for absolute secrecy. He invoked the work of social network theorists, who argued that two people chosen at random would be, at most, three degrees of separation from one another. In other words, the distance between Shannon, Thorp, and an enraged casino owner was slim.

The device that they created "was the size of a pack of cigarettes," operated by Thorp's and Shannon's big toes, "with microswitches in our shoes," and delivered gambling advice in the form of music. Thorp explained:

One switch initialized the computer and the other timed the rotor and the ball. Once the rotor was timed, the computer transmitted a musical scale whose eight tones marked the rotor octants passing the reference mark. … We each heard the musical output through a tiny loudspeaker in one ear canal. We painted the wires connecting the computer and the speaker to match our skin and hair and affixed them with "spirit gum." The wires were the diameter of a hair to make them inconspicuous but even the hair thin steel wire we used was fragile.

Claude Shannon, the Las Vegas Cheat
[Jimmy Soni & Rob Goodman/Nautilus]

A Mind At Play: How Claude Shannon Invented the Information Age [Jimmy Soni & Rob Goodman]

(Image: DobriZheglov, CC-BY-SA)