In games, humans are hopelessly predictable. Spot this hidden behaviour and you can crush puny-minded opponents in everything from the lottery to Rock, Paper, Scissors.

Although we can never outwit the weather or natural disasters, there are ways to master those other seemingly unpredictable entities that control much of your life – other humans. As William Poundstone writes in his new book How to Predict the Unpredictable, if you understand the quirks of human behaviour you can begin to see meaning in our madness, and use that knowledge to our advantage.

It boils down to how human beings find it fiendishly difficult to be random. If you know how to spot this behaviour – and be more random yourself – you’ll soon crush your opponents in the following games:

Rock, Paper, Scissors

This playground game may seem trivial, but it has helped to decide big business deals: in 2005 a Japanese electronics firm asked the auctioneers Christies and Sotheby’s to fight it out for the chance to sell its $20m art collection.

Poundstone points out that men are most likely to throw the more “macho” choice of a rock – while scissors are least popular with both men and women. For these reasons, you are safest choosing paper – you’ll either win or draw. Another cunning trick is to say your choice out loud; your opponent will think you are bluffing and therefore choose a less wise option.

Card games

In games like poker, many people do not bluff at random. If caught out, novices may be reluctant to try the same thing twice. More advanced players may bluff two or three times in a row, but after that, most will stop for fear of appearing to follow a pattern.

Tennis serves

Expect the direction of the serve to alternate, especially when playing a novice. To randomise your own serve, you might use the seconds on your watch, advises Poundstone. From 0-30 seconds, serve on the right; from 30-60 seconds, serve on the left.

The lottery

Lottery draws are random, so it doesn’t matter what other people do, right? Wrong. Although psychology can’t rule the fall of the balls – it can determine the size of your windfall. Thanks to our superstitions and customs, certain numbers tend to be more popular choices than others – meaning that if they come up, the jackpot is shared among more people. On a standard lottery game where you have to choose 6 numbers between 1 and 49, Poundstone says any of the following numbers will give you a better shot at the full jackpot: 10, 20, 29, 30, 32, 38 39, 40, 41, 42, 48, 49. (Of course, if millions of people read this article, then that advice is moot.)

If all this advice feels a little too simplistic, I refer you to the sage advice of literature’s great observer, Sherlock Holmes. "The world is full of obvious things which nobody by any chance ever observes," he says in the Hound of the Baskervilles. It won’t ever guarantee success, but a little knowledge of others’ predictabilities can certainly help to stack the cards in your favour.


William Poundstone’s book How to Predict The Unpredictable: The Art of Outsmarting Almost Everyone is published in the US as Rock Breaks Scissors: A Practical Guide to Outguessing and Outwitting Almost Everybody.

If you would like to comment on this article, or anything else you have seen on Future, head over to our Facebook or Google+ page, or message us on Twitter.