Author Nicholas Derenzo
What if rock, paper, scissors isn’t the fair, balanced, random and unpredictable choosing method you always assumed it was? Recent studies out of China suggest that there may actually be a subtle logic at play in the game—that you might be able to beat a seemingly unbeatable system. As part of the first large-scale study of the game, Zhijian Wang and his colleagues at Zhejiang University divided 360 students into groups, had them play 300 rounds against each other, and then had each person mark down his or her selections. The researchers hypothesized that the results would follow one of the basic principles of game theory, the Nash equilibrium, which states that players benefit from randomizing their choices over time. As expected, each option was in fact chosen about one-third of the time. But, in an unexpected twist, researchers noticed that, in a large group setting, RPS players engage in what’s called a Pavlov (or “win-stay, lose-switch”) strategy. When players win, they’re statistically much likelier to repeat the winning move. But when they lose, they tend to move on to a new choice—specifically in the order of the game’s name, from rock to paper to scissors and then back to rock. The takeaway: If you’re quick enough to anticipate and respond to such patterns, you just might be able to choose that road trip playlist or snag that last slice of pizza.