Some of us might still play the game today, though perhaps the stakes aren’t quite as high as they were when we were kids! Have you, however, ever thought about the strategy behind rock-paper-scissors? Can you, for instance, play in a way that maximizes your chances of winning? The answer is yes, but what may or may not surprise you is that most people don’t take advantage of that fact. Recently, researchers in Zhejiang, China ran one of the largest rock-paper-scissors studies in history. They had 360 people playing with each other in games of rock-paper-scissors, with their strategies carefully documented. To ensure each played to win, they were paid based on how many victories they achieved. Their goal was to see if humans would play the game properly — that is, in the manner that would statistically result in the most victories. This winning strategy is simpler than you might imagine. Indeed, all you have to do is make your selections randomly, or in other words, in each round of rock-paper-scissors, there needs to be a 1/3 chance that you pick either rock, paper, or scissors. But, as the researchers note in their findings (which can be read here), “decision-making and learning are very complicated neural processes,” and thus, what they found surprised them. While the 360 people taking part in the research experiment seemed to choose random selections on average, there was another underlying trend that the researchers found after digging a bit deeper into their findings. What they discovered was that those who won a round of rock-paper-scissors were more likely to stick with the choice that brought them victory. Those who lost, they discovered, were more prone to change their selection. However, what is interesting is that losers chose their next option in a cyclical manner, meaning those who picked rock and lost were more likely to choose paper next, and those who chose paper were more likely to choose scissors, and so on and so forth. This kind of conditional response was dubbed “the win-stay lose-shift strategy,” which has interesting implications when it comes to understanding human nature, and the game of rock-paper-scissors itself. Thus, what the researchers concluded is that victory in rock-paper-scissors isn’t dependent on the classical game theory notion that each player play completely randomly to win the game (otherwise known as the Nash Equilibrium for those of you who remember statistics class). This is because, as the researchers put it, “[rock-paper-scissors] exhibits collective cyclic motions which cannot be understood by the Nash Equilibrium concept but are successfully explained by the empirical data-inspired conditional response mechanism.” Or in other words, to be effective at rock-paper-scissors, you need to know your opponent. Victory is based on reacting to how they play, much more so than it is based on randomly throwing out rock, paper, or scissors. Since this study reveals that most winners stick to their choice, and most losers cyclically move to the next option, you can use that to your advantage to beat novice players of rock-paper-scissors. The researchers do note that experienced players of the game are likely to be reactive to your strategies, and thus are far more difficult to defeat. They also say, however, that facing an opponent good enough to break away from the win-stay lose-shift strategy is “rare,” meaning you can raise your chances of victory (on average) by assuming most humans will stick to the simpler, reflex-based strategy. I think we all sort of knew this though based on our experience with rock-paper-scissors. The game was never about being random, it was about trying to predict your opponent’s tendencies and using them to your own advantage. This research simply confirms that to be the case, and gives us the template by which to achieve as many victories against the average player as possible. These findings might have implications beyond the world of simple hand games as well. If most humans are prone to reflexive choices, rather than reactive ones, then that might say something not only about how our brains are wired, but about how many of the world’s systems work (for example, the financial market). As such, the researchers say that their next study will be going more in-depth in terms of investigating the nature of our “irrational” choices. While there are still many more questions to be answered, you can at least rest easy knowing that with the knowledge above, you’ll be able to outplay the majority of the human population when it comes to rock-paper-scissors. Just be sure you don’t challenge someone who’s also familiar with this strategy, else you might have to up your game just a little bit! Featured photo credit: Rock Paper 4 via thenypost.files.wordpress.com
