How to predict the unpredictable

We are hard-wired to believe that the world is more predictable than it is, says best-selling author William Poundstone. We chase ‘winning streaks’ that are often just illusions, and we are all too predictable exactly when we try hardest not to be, thus exposing the universal human weakness ‘our inability to recognise or produce randomness’.

In the 1970s, Daniel Kahneman and Amos Tversky coined the phrase ‘representativeness’ to describe the psychology of this behaviour. Since then, representativeness has been used by auditors to catch people fiddling their tax returns and by hedge fund managers to reap billions from the emotions of small investors.

You can outguess people and computers by detecting their all-too predictable ‘random’ decision-making patterns, says Poundstone. Here’s how:

How to outguess the lottery:

Choose these lucky numbers because relatively few players pick them, reducing the chance of a shared jackpot: 10, 20, 29, 30, 32, 38, 39, 40, 41, 42, 48, 49

How to outguess multiple-choice tests:

• On true-false tests, ‘true’ answers are more common.
• On multiple choice tests with four answers, the second one – b – is more often correct.
• A strategy for standardised tests like the SAT is to eliminate the outlier. Avoid guessing an answer that is too different from the others.

How to outguess Rock, Paper, Scissors:

Scissors in the least popular choice, and men favour Rock. Both are good reasons to choose Paper in a one-shot match.

How to forecast the future:

Research argues that business and political forecasters are not much more accurate than educated non-experts. Most forecasting will invoke the belief that trends will continue in the near future. This is not necessarily true, but more likely to be remembered. Whatever happens last in a slideshow, presentation or meeting is most likely to be remembered so successful forecasters are good at creating strong last impressions.

How To Predict The Unpredictable: The Art Of Outsmarting Almost Everyone by William Poundstone is published by Oneworld and costs £12.99

Photograph: Corbis