The question of how to win at rock-paper-scissors has， believe it or not， plagued mathematicians and game theorists for some time. While they previously had devised a theoretical answer to the question， an experiment by Zhijian Wang at Zhejiang University in China （PDF） that used real players has revealed an interesting wrinkle to the original theory.
In the experiment， Zhijian noticed that winning players tended to stick with their winning strategy， while losers tended to switch to the next strategy in the sequence of rock-paper-scissors， following what he calls “persistent cyclic flows”.
While the Nash Equilibrium should be the best strategy in real life， Zhijian found a decidedly different pattern when he and some other researchers recruited 72 students to play the game。 They divided the students into 12 groups of six players and had them each play 300 rounds of rock-paper-scissors against each other. Zhijian also added a payout in proportion to the number of victories.
The pattern that Zhijian discovered - winners repeating their strategy and losers moving to the next strategy in the sequence - is called a ‘conditional response’ in game theory.The researchers have theorised that the response may be hard-wired into the brain， a question they intend to investigate with further experiments.