How to win at rock-paper-scissors

[dipsydoodle]

What are your odds of winning rock-paper-scissors? Simple - one in three. At least, that's what chance predicts.

But people do not play randomly - they follow hidden patterns that you can predict to win more games than you should, a study has revealed.

Winners tend to stick with their winning action, while losers tend to switch to the next action in the sequence "rock-paper-scissors".

Anticipating these moves could give you a winning edge, say scientists.

Their strategy was revealed in a massive rock-paper-scissors tournament at Zhejiang University in China, documented on the Arxiv server.

http://www.bbc.co.uk/news/science-environment-27228416

[truebrit71]

1. ...or use the updated version of Rock, Paper, Scissors, Lizard, Spock...

[RGinNJ]

2. Bang!

[giftedgirl77]

5. Bazinga...

[DetlefK]

3. So, the best strategy is...

If you loose, stay random.
If you win, your opponent will pick what did beat him (=what you just had), so pick the sign to beat yourself.

Unless, your enemy knows that you know that he will pick what you just had and that you will pick the symbol one step prior in the sequence, so he will keep with his choice (e.g. paper) while you switch yours (e.g. from scissors to rocks) and this time he beats you.

The trick is to know that your enemy knows that you know that he will...

[Johonny]

4. best strategy is

not to play.

[DetlefK]

7. But then your odds of winning shrink to 0%.

[Johonny]

11. you clearly never watched War Games

when winning is meaningless and losing sucks, don't play.

[qazplm]

10. the best strategy

is to be slower than your opponent (so that you can see what he's going to pick) but fast enough that you don't get caught cheating.

[unblock]

9. the best strategy is to pick whatever beats whatever just won, regardless.

your opponent is likely to pick the previously winning play, regardless of who won.

of course, if you're playing against a thinking opponent for any reasonable amount of time, you have to randomize your strategy a bit, lest your opponent figure out what you're doing and adapt. just make sure you're doing the above strategy a bit more than random.

[stone space]

12. Randomizing your strategy in real time is easier said than done, unless...

...you have access to a list of pseudorandom numbers that you are hiding from your opponent, and time to consult it between plays.

Of course, if you have a good memory, you could memorize it beforehand, I suppose.

you have to randomize your strategy a bit, lest your opponent figure out what you're doing and adapt.

[unblock]

13. here's a trick that help:

it's easier to use when i want to randomize my poker strategy, but you could do it in this game as well with the right watch:

base your strategy on the second hand of a watch or clock, preferably where only you can reasonably see it. a simple plan is to take the number of seconds, divide by 3, and if the remainder is 0, 1, or 2, you pick rock, paper, scissors respectively.

of course this doesn't work if each round takes the exact same number of seconds! but if you're laughing and chatting in between it should be fine. just place your wristwatch where you can discreetly see it. a watch with large digital seconds displayed would help.


obviously this isn't completely random either, but at least it gets away from the kind of patterns you'd otherwise fall into.
i agree with your point, as does the article, true or even reasonable randomness is hard to achieve. that's kinda the whole point.

[stone space]

14. That's a good idea. It is fortunte that 60 is divisible by 3, since otherwise, the calculations...

...could be difficult to do in you head in real time.

[Wounded Bear]

6. I thought you were going to say...

1. Make the Rock sign with your fist.

2. Hit opponent in the nose.

[JayhawkSD]

8. Use the Indiana Jones method

While your opponent is counting down for the big moment, take out your pistol and shoot him.