Rock, Paper, Scissors.

[YourFoxyGrandma]

Is Rock, Paper, Scissors (or some permutation thereof) beatable? I had always assumed that you could gain some sort of psychological advantage over your opponent, but thinking about it, it seems more like a crapshoot.

[ddollevoet]

It is beatable if you know your opponent. Otherwise it is a crap shoot.

When I was in the dorms at college, my roommate and I ordered pizza all of the time (usually 3-4 times a week). Since the pizza guy would not come up to our room, someone always had to go downstairs and pay the guy and get the pizza.

My roommate and I used to hate to have to do this, so we started playing rock, scissors, paper. The loser had to go down, pay the guy and get the pizza.

I doubt that I had a psychological advantage, but I rarely lost. When the phone would ring to alert us that the pizza guy was there, we would automatically play rock, scissors, paper. No thought or planning just go.

I never lost after a brief analysis of his play.

My roommate always picked rock. ALWAYS.

[edtost]

if your opponent is not randomizing perfectly (1/3 r, 1/3 p, 1/3 s, iid for each round), perfect randomization will come out ahead in the long run, and an exploitive strategy will do even better, at least in the short run.

[pshreck]

No one ever starts with paper. Ever.

[schwza]

i'm am sure that if an unknown opponent throws rock, he is [more or less] likely to throw rock on the next throw. i just don't know which. but obviously, that would be useful information.

my guess would be something like: throw something once, 35%+ to throw it again, and if you've thrown something 3 times in a row, 20% or less to throw it a 4th. but i'm just guessing.

[Rick Diesel]

Someone needs to introduce you to the Tiltboys and the world of Roshambo.

[jakethebake]

Ask these guys...


World International Rock Paper Scissors Championships (http://www.rpschamps.com/)

[rusellmj]

Ask this guy (http://www.andybloch.com/gl/pub/index.php), he's a world champion from what I understand.

Russ

[Clarkmeister]

Good ole rock. Rock always wins.

[ddollevoet]

[ QUOTE ]
Good ole rock. Rock always wins.

[/ QUOTE ]

That's what my roommate thought.

[YourFoxyGrandma]

Haha. Wow. (http://www.simonsays.com/content/content.cfm?sid=33&pid=501048)

I need this.

[Popinjay]

[ QUOTE ]
[ QUOTE ]
Good ole rock. Rock always wins.

[/ QUOTE ]

That's what my roommate thought.

[/ QUOTE ]

Bart too.

[Eihli]

Poor predictable Bart, always chooses rock.

[Sephus]

[ QUOTE ]
if your opponent is not randomizing perfectly (1/3 r, 1/3 p, 1/3 s, iid for each round), perfect randomization will come out ahead in the long run

[/ QUOTE ]

wrong. if you randomly play each with 1/3 probability, you win 1/3, tie 1/3, and lose 1/3 no matter what your opponent does.

[edtost]

blah, i suck. if your opponent does not randomize that way, however, an exploitive strategy can always be created.

[pokerjo22]

The answer is probably in this book:

Rock, Paper, Scissors Strategy Guide (http://www.simonsays.com/content/content.cfm?sid=33&pid=501048)

[jakethebake]

Clearly the optimal strategy is to use the second hand of your watch to reandomize perfectly.

[BWebb]

[ QUOTE ]
Good ole rock. Rock always wins.

[/ QUOTE ]

This is true. Rock flies through paper.

[edtost]

unless you opponent sees you looking at your watch and looks at his, which would make you exploitable.

[shant]

I made a shirt related to the power of Rock in this game. I won't spam but you can find a link to it in my profile.

[housenuts]

whose watch is set exactly the same as their friends? sounds like bum buddies to me.

i have a sequence i always use. rock, rock, paper, rock, scissors, paper, rock, scissors, scissors, paper, rock, paper

[Dynasty]

[ QUOTE ]
Good ole rock. Rock always wins.

[/ QUOTE ]

I believe the quote is "Good ole rock. Nothing beats that......d'oh.

[waffle]

A bunch of opponents have a common tendency: They attempt to mix up their throws randomly,but they do not like to throw the same weapon twice in a row. If I chose rock the previous round, the least exploitable strategy dictates I throw R,P,S with frequency .33, .33, .33. However, many opponents will throw with frequencies more like .15, .42, .42 due to their aversion of throwing the same weapon twice in a row.

The correct strategy to exploit this is obvious.

[jakethebake]

[ QUOTE ]
A bunch of opponents have a common tendency: They attempt to mix up their throws randomly,but they do not like to throw the same weapon twice in a row. If I chose rock the previous round, the least exploitable strategy dictates I throw R,P,S with frequency .33, .33, .33. However, many opponents will throw with frequencies more like .15, .42, .42 due to their aversion of throwing the same weapon twice in a row. The correct strategy to exploit this is obvious.

[/ QUOTE ]

Aaah. But if they're good, they'll know you'll try to exploit this.

[DcifrThs]

Me and my bro would play a best 4/7 series of 4 matches of RPS. each match was best 4/7.

he used to beat me all the time, then i started to get into his head and killed him for a long time...now i think id like to just do it randomly...

what is the best method to randomize your play on the fly...i.e. i can't roll a die with 1/2=rock 3/4=paper 5/6=scissors...but i want the same effect.

-Barron

[waffle]

That is true. You can play the least-exploitable strategy, .33 .33 .33. Or you can attempt to exploit your opponent as much as possible if you have a good model of his strategy. This will always open yourself up for counterattacks.