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Add randomness to your serve to improve your game (Image: Koji Aoki/plainpicture)

From tennis to the stock market, How to Predict the Unpredictable by William Poundstone aims to teach you how to overcome a universal human weakness

THE was renowned as the father of information theory. But his colleagues at Bell Labs also knew him as a unicyclist, a juggler and the designer of an electromechanical mind-reading machine. In the early 1950s it was a big attraction at Bell, consistently predicting people鈥檚 behaviour in a guessing game by detecting patterns in their guesses. Only Shannon could beat it.

As William Poundstone explains in How to Predict the Unpredictable, the machine鈥檚 power wasn鈥檛 down to its clever design but the fact it exploited a universal human weakness, 鈥渙ur inability to recognize or produce randomness鈥�.

Poundstone鈥檚 book takes up where the mind-reading machine left off, with the aim of helping everyone achieve Shannon鈥檚 guessing savvy. In other words, this book is a guide to outguessing people and computers by detecting their decision-making patterns. It鈥檚 also a tutorial in how to prevent others from anticipating your own behaviour.

One realm in which readers can readily benefit by outguessing is standardised testing, since the pattern of correct answers is rarely truly random. Whether the tests are true/false or multiple-choice, and whether they are algebra quizzes or professional exams, examiners tend to make the same distribution errors.

For instance, in the effort to randomise the occurrence of true and false statements, most test writers will toggle between true and false more regularly than would happen by chance. They seldom put three false statements in a row, says Poundstone. So if there are false statements surrounding the one stumping you, you would be smart to bet that the statement is true.

聯If false statements surround the one stumping you, you鈥檇 be smart to bet that the statement is true聰

What happens in the classroom also applies on the tennis court. When trying to predict whether an opponent will serve to your left, right or straight, you can expect them to switch more frequently than would happen at random. Poundstone observes that you can improve your game by not making the same mistake. Since true randomness is so hard to fake, you can mix up your serve by dividing a watch dial into three sectors 鈥� signifying left, right and centre 鈥� and glancing at the position of the second hand immediately before serving.

Poundstone methodically covers subjects ranging from lotteries to passwords to stock markets, providing advice that鈥檚 practical, but ultimately becomes, well, stultifyingly predictable.

However, his underlying argument is both valid and vital. As he notes in his prologue, 鈥渢he most important outguessing machine is the one known as Big Data鈥�. Shannon鈥檚 mind-reading technology has become unavoidable and ubiquitous. The only escape is randomness.

This article appeared in print under the headline 鈥淓scape to random鈥�