Want to win at rock-paper-scissors? Here's how

A Chinese mathematician believes there's a "conditioned response" in the playing patterns of the famous game.

Between rock and a hard place? Videojug/YouTube screenshot by Chris Matyszczyk/CNET

It's the sheer randomness of life that forces us to embrace certain random games.

Or, at least, games that appear random.

The charming boffins of Las Vegas understand this. We pore over roulette wheels, in the belief that only the gods can control which number will come up.

Indeed, I once read a charming tale that when income was slipping at the roulette wheel, the casinos decided to put up displays of the previous numbers that had come up. As if this had any bearing on which number would come up next. The display apparently had a significant impact on profits.

And so we come to rock-paper-scissors. This game, learned in childhood by most, has been used to sort out everything from who will get the last candy to who will stay in a marriage.

It seems to be quite arbitrary. All we're trying to do is guess what the other player will offer and ensure we will beat it. Although, there is, of course, already a robot that wins all the time.)

A Chinese mathematician, however, believes that human minds play rock-paper-scissors according to defined patterns.

As the MIT Technology Review reports, those who theorize about these things always believed that the best way to win at rock-paper-scissors was to just choose a weapon at random.

However, Zhijian Wang at China's Zhejiang University decided to study 360 people to see how they played. Sadly, these people were students. But one can only hope that his results might be replicated across all humanity.

At first, it seemed as if everyone really was just choosing a weapon at random. On further review, though, Wang and his team realized that those who won the last round had a tendency to choose the same weapon for the next one. Conversely, those who lost a round were far more likely to go for a different weapon. Just, you know, to change their luck.

Moreover, the losers would work in what Wang called a clockwise direction. They went from rock to paper to scissors. This he described as a "conditional response."

Naturally, being a mathematician, he offered the MIT Technology Review an erudite quote: "This game 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."

If his results turn out to have even deeper psychological underpinnings, they would surely enhance the chances for those with a new insight into their opponent's thinking.

There again, if everyone learns of Wang's hypothesis, then the whole world will start playing rock-paper-scissors in a different manner and we'll be back to the same random mess again.

One more thing for a scientist to explain: Why does paper beat rock? Surely rock can rip right through paper.

Sorry, I've just always wanted to ask someone that.

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