As long as I can remember, children – and others – have played rock-paper-scissors, also called roshambo. Sometimes it’s played as a game, usually between two players. Other times it’s used as a way to choose, for example, who goes first in a game or who pays for lunch.
In rock-paper-scissors, players use their hands to make a gesture (a movement that means something) for rock, paper, or scissors (see the photo or click here for a larger one). You win if your gesture beats (wins over) the gesture of your opponent (the person you are trying to beat).
Here’s how the gestures work:
- Rocks break scissors, so rock beats scissors.
- Paper covers rock, so paper beats rock.
- Scissors cut paper, so scissors beats paper.
Here’s how we used to play rock-paper-scissors: To prepare to play, each player puts his/her fist (closed hand) on the palm (inside) of his/her other hand – like putting a cup on a saucer (small round plate). They then raise and lower their fists together (at the same time), hitting their palm each time. The third time, they make the gesture they have chosen – rock, paper, or scissors. The winner is the player whose gesture beats his opponent’s. If the players make the same gesture, they repeat the process until one player wins.
I hadn’t thought about rock-paper-scissors for a long time. Then the other day I saw an article in the Washington Post that promised to tell me How to win rock-paper-scissors (almost) every time. I like to win, so that got my attention!
We usually assume (believe without proof or evidence) that people who play games like rock-paper-scissors make random (without a plan or pattern) choices when they choose which gesture to use. Scientists in China recently studied 360 subjects (people tested in a research study) to see if that is true. And they discovered that it’s not.
Here’s what they discovered:
- If a player wins the first time, he/she will repeat the same gesture.
- If a player loses, he/she will change gestures in a predictable (expected) way: rock to paper, paper to scissors, and scissors to rock.
You can use that information to help you win the next time you play rock-paper-scissors. Let me show you how. Imagine that my friend and I are trying to decide who pays for lunch. We’re going to play best of three (one of us must win twice):
- The first time my friend plays paper; I play rock. He wins.
- The second time my friend plays paper (because paper won the first time); I expect him to play paper again because he won, so I change to scissors. I win. Since we have both won once, we have to play one more time.
- The third time my friend changes to scissors (because paper lost last time); I expect him to do that, so I change to rock. I win again! And my friend has to pay for lunch.
I haven’t played rock-paper-scissors for many years, but the next time Jeff and I have lunch together, I think I’ll see if he wants to roshambo to see who pays. I hope he doesn’t read this. I’d like to win!
Have you ever played rock-paper scissors?
~ Warren Ediger – ESL coach/tutor and creator of the Successful English web site.
Photo courtesy of Wikipedia Commons.