The Nash Equilibrium of Rock, Paper, Scissors
Source: http://www.bbc.co.uk/programmes/b0640tzr
At a small bar in Philadelphia, a group of young people gathers religiously to play strategic games of Rock, Paper, Scissors (RPS). These RPS fanatics say that the key to winning games consistently is by reading a person’s physical patterns and thinking one step ahead of their moves. This is fairly common for most games, however, when everyone is an expert, the players must expect that their opponents are thinking one step ahead as well. There are three specific strategies that players can follow but because they are so well known, there is no use in playing the strategies. Many experts find themselves going down the rabbit hole of prediction. “If my opponent knows that I know their main strategy, they will play the opposite of the strategy, but if they know I know they wont play the opposite strategy, they will play the original…” and exedra. Fortunately, there are only three choices of play in RPS so the predictions of opponent’s strategies repeat themselves.
In class we learned that the Nash Equilibrium is the strategy of a game where no player has an incentive to change his or her strategy no matter what other players choose. Game theory suggests that a purely rational game would involve players guessing infinitely far ahead of their opponents moves, this is why the Nash Equilibrium of RPS is playing randomly. However in this podcast Jolyon Jenkins explains the ways in which humans are not completely rational, nor can they function completely ad random. It is the players that can be most aware of choosing randomly and picking up on human patterns that win most consistently. This shows that the Nash Equilibrium is not the most effective strategy in real life games of RPS.