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Comment by vinceguidry | Hacker News Reader

If you made random moves in a game of chess or checkers you'd get beat by a four year old with the barest grasp of the rules. In fact I would love to see a chess-playing robot that actually does that, it would thrill the crap out of my nephews to beat the big bad robot in a game of wits.

I'm unaware of the name of the property that RPS exhibits that makes it ungameable by a random opponent (zero-sum?) but ordinary RPS played by humans certainly doesn't exhibit it, only in the magic world of computers where things like simultaneity of play can be guaranteed does RPS exhibit that property.

If played in the real world like real humans traditionally played it, ongoing RPS matches between a human and an AI would soon see the AI dominating. I'd be very curious to see what real-world RPS would look like between two AIs that can 'explain their model'.

Imagine making a rule that gives a Xms window for making plays. Then strategy can start to emerge.

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2 person adversarial games with hidden information (eg poker or RPS) exhibit a "Nash equilibrium in mixed strategies". That is, the best strategy involves a random selection between choices with some probability weights. Since RPS is a very simple game, the weights are equal, so the unbeatable strategy is to choose between rock, paper and scissors with uniform probability on each round taking no account of what you or the other player have played before. Any other strategy can be exploited to the extent it deviates from pure uniform random choice (eg trivially the classic "play the thing that would have beat the thing which beat the winner of the previous round" strategy in RPS which you can use to reliably destroy children at the game).

Games with complete information (eg noughts and crosses, chess, go etc) have "pure strategies" (ie randomness is not required and there should always be an absolute best move in any given situation which you should pick 100% of the time).

Here's an intro to the concept of Nash equilibrium in mixed strategies http://www.econport.org/content/handbook/gametheory/useful/e...

Edit: In case it's not clear, the hidden information in RPS is the opponent's move. Whereas in chess you are either starting the game or you know what the opponent has done, in RPS you move simultaneously with the opponent, so don't know their move.

The Internet truly is a horn of plenty. Thanks for granting my nerd wish!

The Nash-Equilibrium solution to RPS is playing each option a third of the time. Simplified, this means that if you're playing this strategy, your opponent's best strategy is to do the same and there is nothing either of you can do to increase your own expectation.

This thread is talking about playing random -- by aid of a computer providing random numbers. The result is just that -- 1/3 of the time each option is played. The issue here is this AI is able to best random, and that is not something that should happen.

This is not chess. But a game of chance. You can't form a strategy based off random without predicting said random.

I thik it was already pointed out but I have not had a chance to verify. This game uses your played move in tht training set to train before making it's predictions.

RPS is not a game of chance. Outcomes of games are determined not by a random process, but by the choices of the players.

If the players rolled dice and biggest roll wins, that's a game of chance. The dice can't pick how they're thrown, nor can the throwers influence the outcome. If either of those two things change, the game is no longer purely one of chance.

The game can be set up in many ways that invite strategy. If they set up a camera and watched the human playing out the moves physically, that lets the algorithm read the person's patterns the way a human might read someone's poker tell.

It becomes a game of chance once one of the players is replaced with a computer picking at random.

Which is the point of this thread. Random vs AI.

That's gotta be the most boring discussion ever. I guess I'll leave you to it.

Are you implying that you can (or any other human can) in the long run beat someone who is playing RPS randomly?

Can I beat a computer playing randomly, no. A human, show me where the random number generator in their brain is.

I see the confusion now.

The entire point of this thread is that some of use pitted random vs this AI. And tht AI is winning more often than it should. Zero humans were involved.

Which brings us back to you can't game random.

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