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A Chinese Mathematician Figured Out How To Beat Anyone At Rock-Paper-Scissors
Business Insider ^ | 05/02/2014 | HARRISON JACOBS

Posted on 05/02/2014 4:09:01 PM PDT by SeekAndFind

The question of how to win at Rock-Paper-Scissors has, believe it or not, plagued mathematicians and game theorists for quite some time. While they previously had devised a theoretical answer to the question, a new experiment by Zhijian Wang at Zhejiang University in China that used real players, has revealed an interesting wrinkle to the original theory.

In the experiment, Zhijian noticed that winning players tended to stick with their winning strategy, while losers tended to switch to the next strategy in the sequence of rock-paper-scissors, following, what he calls, “persistent cyclic flows.”

Here's how it works in practice: Player A and Player B both start by using random strategies. If Player A uses rock and Player B uses paper, Player A loses. In the next round, Player A can assume that Player B will use paper again and should therefore use scissors to win. In the round after that, because Player B lost, Player A can assume that Player B will use the next strategy in the sequence — scissors — and Player A should then use rock, thus winning again.

If you take the game on a theoretical level, the most mathematically sound way to play Rock-Paper-Scissors is by choosing your strategy at random. Because there are three outcomes — a win, a loss, or a tie — and each strategy has one other strategy that it can beat and one other strategy that can beat it, and we don’t care what strategy we win with, it makes the most sense to pick paper exactly 1/3 of the time, rock 1/3 of the time, and scissors 1/3 of the time. This is called the game's Nash equilibrium.

TOPICS: Science
KEYWORDS: math; nashequilibrium; rockpaperscissor

1 posted on 05/02/2014 4:09:01 PM PDT by SeekAndFind

To: SeekAndFind

2 posted on 05/02/2014 4:13:08 PM PDT by goodwithagun (My gun has killed fewer people than Ted Kennedy's car.)

To: SeekAndFind

Chinese mathematician vs. Japanese robot: https://www.youtube.com/watch?v=3nxjjztQKtY

(Actually, it isn’t a Chinese mathematician on the left, but it might as well be.)

3 posted on 05/02/2014 4:15:23 PM PDT by coloradan (The US has become a banana republic, except without the bananas - or the republic.)

To: SeekAndFind

This is Hugh and Series, why isn’t it in Breaking news?

4 posted on 05/02/2014 4:16:36 PM PDT by PROCON (Those who are capable of Tyranny are capable of Deceit to sustain it.)

To: SeekAndFind

No mathematician would trouble themselves with this foolishness for even a second.
.

5 posted on 05/02/2014 4:19:44 PM PDT by editor-surveyor (Freepers: Not as smart as I'd hoped they'd be)

To: goodwithagun

I think Kramer figured it out before that: Rock beats everything.

6 posted on 05/02/2014 4:19:57 PM PDT by gundog (Help us, Nairobi-Wan Kenobi...you're our only hope.)

To: SeekAndFind

In other words its impossible to do anything randomly because there is no such thing.

7 posted on 05/02/2014 4:21:00 PM PDT by Theophilus (.)

To: SeekAndFind

Most players choose rock for their opening hand, because since it represents a fist, it projects a powerful image.

Paper, in fact, is the most powerful and underappreciated weapon in the game.

8 posted on 05/02/2014 4:23:22 PM PDT by Extremely Extreme Extremist (100% pure organic, free-range conservative)

To: SeekAndFind
Nash says he recovered his sanity "with the rejection of politically oriented thinking as essentially a hopeless waste of intellectual effort."

Touché!

9 posted on 05/02/2014 4:28:46 PM PDT by MUDDOG

To: SeekAndFind

What happens if he plays a round with another chap using the same formula ?

10 posted on 05/02/2014 4:31:55 PM PDT by wonkowasright (Wonko from outside the asylum)

To: editor-surveyor

This is very serious stuff, it might win wars.

11 posted on 05/02/2014 4:35:32 PM PDT by Vinylly (?%)

FR Needs Donors To Survive

12 posted on 05/02/2014 4:35:54 PM PDT by DJ MacWoW (The Fed Gov is not one ring to rule them all)

To: gundog

Rock flys right thru paper

13 posted on 05/02/2014 4:38:20 PM PDT by snappahead (if your gonna be dumb, you better be tough.)

To: Vinylly

If you read the article cogently, they are saying that there is no system to win.

Consistency is the only way to keep it even 50/50.

14 posted on 05/02/2014 4:44:10 PM PDT by editor-surveyor (Freepers: Not as smart as I'd hoped they'd be)

To: wonkowasright

They both win.

15 posted on 05/02/2014 4:45:39 PM PDT by DuncanWaring (The Lord uses the good ones; the bad ones use the Lord.)

To: SeekAndFind

So THIS is what the Chinese are doing with all our money!

Worthless research and easy jobs for so-called scientists, well, they learned it from the best...us.

16 posted on 05/02/2014 4:46:18 PM PDT by Beowulf9

To: SeekAndFind

I’ve never really played that game and can’t say that I really understand it. Is there some sort of hierarchy as far as what you can begin with, or is it whatever you decide to go with? Are there further “rounds” in the same game or is it like flipping a coin?

17 posted on 05/02/2014 4:53:55 PM PDT by RegulatorCountry

Yeah. Pretty funny watching Mickey and Kramer playing rock vs. rock.

18 posted on 05/02/2014 4:54:45 PM PDT by gundog (Help us, Nairobi-Wan Kenobi...you're our only hope.)

To: goodwithagun

Depending on the stakes, I prefer “Rock - Paper - Scissor - Glock”.

19 posted on 05/02/2014 4:54:51 PM PDT by Kickass Conservative (Nobody owes you a living, so shut up and get back to work...)

To: Kickass Conservative

20 posted on 05/02/2014 5:04:55 PM PDT by KC_Lion (Build the America you want to live in at your address, and keep looking up.- Sarah Palin)

To: RegulatorCountry

It’s similar to Tic Tack Toe. A waist of time brought on by boredom. I won’t get into the merits of doing a study on Rock, Paper, Scissors game theory.

21 posted on 05/02/2014 5:05:42 PM PDT by Lurkina.n.Learnin

To: SeekAndFind

22 posted on 05/02/2014 5:09:04 PM PDT by dfwgator

To: SeekAndFind

Has he figured out how to beat the chicken playing tic tac toe yet?

23 posted on 05/02/2014 5:19:21 PM PDT by rawcatslyentist (Jeremiah 50:32 "The arrogant one will stumble and fall ; / ?)

To: rawcatslyentist

“Has he figured out how to beat the chicken playing tic tac toe yet?”

Don’t let the chicken go first.

24 posted on 05/02/2014 6:01:32 PM PDT by EQAndyBuzz ("Heck of a reset there, Hillary")

To: goodwithagun

25 posted on 05/02/2014 7:10:18 PM PDT by EEGator

To: EEGator

I’m not crazy. My mother had me tested.

26 posted on 05/02/2014 7:13:08 PM PDT by goodwithagun (My gun has killed fewer people than Ted Kennedy's car.)

To: goodwithagun

I thought it was rock-paper-scissors-match-gun.

Let’s see....scissors cuts paper, rock smashes scissors.
paper smothers rock. Match burns paper but scissors cuts match.....meaning that paper beats gun, and gun beats scissors.

R P S M G
R 0 - + ? ?
P + 0 - - +
S - + 0 + -
M ? + - 0 ?
G ? - + ? 0

Dang, I forget....rock beats either match or gun and loses to the other. If rock beats match then match beats gun.
If rock beats gun then gun beats match.

What the heck is lizard? Is Spock the “live long and prosper” or the Vulcan nerve pinch....that’s close to gun.

27 posted on 05/02/2014 7:17:14 PM PDT by scrabblehack

To: EEGator

“paper disproves Spock”

lol!

28 posted on 05/02/2014 7:21:05 PM PDT by Yardstick

To: scrabblehack

It’s from the Big Bang Theory sitcom.

29 posted on 05/02/2014 7:25:41 PM PDT by goodwithagun (My gun has killed fewer people than Ted Kennedy's car.)

To: SeekAndFind

Choosing scissors can get you expelled from school.

So keep choosing paper to bait your enemy into choosing scissors.

30 posted on 05/02/2014 7:46:33 PM PDT by UnwashedPeasant

To: dfwgator

Hah...very good. :-)

31 posted on 05/02/2014 11:05:08 PM PDT by Conservative4Ever (waiting for my Magic 8 ball to give me an answer)

To: goodwithagun
Sheldon is a great character.
32 posted on 05/03/2014 3:20:49 AM PDT by EEGator

To: goodwithagun; EEGator

Mine is from my misspent youth when we got bored from rock-paper-scissors. Although it raises some interesting questions:

How do match and gun fare against lizard and Spock?
Obviously one of each set has to beat one of the other set.

I think gun has to shoot lizard but then Spock vaporizes gun.
Which means that lizard eats match but match burns Spock.

I am thinking that match burns rock....the rock is a lump of coal or something. Which means that rock smashes gun, and gun lights match.

Also it looks like Spock is the Live Long and Prosper sign.
How is lizard formed? Post 25 looks a little too close to rock.

33 posted on 05/03/2014 8:17:43 PM PDT by scrabblehack

To: goodwithagun; EEGator

Better story: Spock realizes the gun isn’t real (allusion to the episode Spectre of the Gun).

34 posted on 05/08/2014 7:17:10 PM PDT by scrabblehack

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