I’m currently in Atlanta, where this week a large group of us planned work for the next three months. And to wake people up in the morning for fun, we organized a hall to play rock-paper-scissors to find the absolute winner of the hall. Where I realized, I cannot play the American version of rock-paper-scissors. In the USA, they play it like this: they beat their fist on the palm on “rock”, then beat on “scissors”, then beat on “paper”, and then they say “shoot” and show their hand. Generally, we also have four counts (“rock, scissors, onion, mage”), but it’s not quickly apparent because there are exactly three words and no “shoot”. (Also, we have a longer version “rock, scissors, onion, mage, tsu, ye, fa”; however, in the USA, a version without “shoot” is also common)
Obviously, against a random number generator any strategy you take, the probability is 30%. But there are interesting studies on how to play against real people. Here are its findings:
1) winners repeat: people tend to repeat what helped them win last time. If you showed rock and won against scissors, you are more likely (than 1/3) to show rock again.
2) losers change: when losing, people tend to change strategy (showed rock, lost, why show it again)
From this, some hints on how to win:
1) if you lost, in the next round show what was not shown this time (if rock and scissors were shown, show paper)
2) if you won, then in the next round show what your opponent lost with the previous time
3) if it’s a tie, choose randomly
By the way, there’s a robot that wins at “Rock-Paper-Scissors” 100% of the time. But it cheats – it watches the micro-movements of your hand and anticipates by showing the opposite. Google “Janken Robot”
Hi, I'm Rauf Aliev. 