It’s About Time: Science Finds a Winning Strategy for Rock-Paper-Scissors


Researchers at several Chinese universities gathered together 600 students and pitted them against each other in a rock-paper-scissors battle. To the death. The whole thing was an attempt to find pattern and hopefully a winning strategy.

What they found was that “if a player wins over her opponent in one play, her probability of repeating the same action in the next play is considerably higher than her probabilities of shifting actions.” If a player has lost two or more times, she is likely to shift her play, and more likely to shift to the play that will beat the one that has just beaten her than the same one her opponent just used to beat her. For instance, if Megan loses by playing scissors to Casey’s rock, Megan is most likely to switch to paper, which would beat Casey’s rock. Per the research, this is a sound strategy, since Casey is likely to keep playing the hand that has been winning. The authors refer to this as the “win-stay, lose-shift” strategy.

Want to know how I win all the time. I play things that aren’t allowed. Like dynamite and handgun. Yep I’m that jerk. I’m also likely to hit you with a real rock if you tell mom so let’s keep this between us.