Rock Paper Scissors

Darn, now the Chinese will beat us at rock-paper-scissors too:

It turns out that the best strategy is to choose your weapon at random. Over the long run, that makes it equally likely that you will win, tie, or lose. This is known as the mixed strategy Nash equilibrium in which every player chooses the three actions with equal probability in each round.

And that’s how the game is usually played. Various small-scale experiments that record the way real people play Rock-Paper-Scissors show that this is indeed the strategy that eventually evolves.

Or so game theorists had thought. Today, Zhijian Wang at Zhejiang University in China and a couple of pals say that there is more to Rock-Paper-Scissors than anyone imagined. Their work shows that the strategy of real players looks random on average but actually consists of predictable patterns that a wily opponent could exploit to gain a vital edge...