Researchers at Zhejiang University in China used classical game theory to analyse the moves of 360 volunteers in a rock-paper-scissors tournament.
Classical game theory suggests players make random choices. In the case of rock-paper-scissors it is believed that players select one of three options with equal probability in each round. This can be explained through the Nash equilibrium concept, which was developed by John Forbes Nash Jr, the scientist famously portrayed by Russell Crowe in the 2001 movie A Beautiful Mind.
In the Chinese tournament each participant chose either rock, paper or scissors about a third of the time, just as the Nash equilibrium predicts. However, the researchers found another pattern, the one that will actually help you win -- and it's based in the ‘win-star lose-shift’ strategy.
Players who take a round stick to their winning option more often than expected. Losers, on the other hand, switch to a different action in the following round, but tend to do it the order of the game. If, for example, they lost with paper, players are more likely to choose scissors in the next round; if they lost with rock, chances are they will play paper.
The ‘win-star lose-shift’ strategy is a conditional response in game theory that researchers believe is hard-wired into the human brain. Figuring it out after one or two rounds shouldn’t be that hard.
The paper “Social Cycling and Conditional Responses in the Rock-Paper-Scissors Game” was published in arxiv.org, click here if you want to read it before signing in for the Rock Paper Scissors World Tournament.
Now, we are not entirely sure if this strategy works if you are playing rock-paper-scissors-lizard-Spock with a fan of Dr Sheldon Cooper...