Good old Rock. Nothin' beats that!

For those of you who missed the All Japan Ninja Championships (and you know who you are), I sadly inform you that you may have also missed the 2003 World Rock Paper Scissors Championship.

You might think this championship will necessarily determine the best Rock Paper Scissors player in the world. But you would be wrong.RockPaper.jpg

According to the official rules, finalists and semi-finalists will be chosen using a single-elimination format. However, consider the following scenario:

One player - let us call him Mr. Rock - always beats his friend, whom we shall call Mr. Scissors. And Mr. Scissors, although not quite as skilled as Mr. Rock, always beats another player, Mr. Paper.

So, transitively, Mr. Rock should always beat Mr. Paper, right? Unfortunately for Mr. Rock, Rock Paper Scissors, like voting, is not transitive.

In other words, order matters. If Mr. Rock plays against Mr. Scissors in the qualifying rounds, the outcome of the tournament will be quite different than if Mr. Rock is pitted against Mr. Paper.

Thus, I'm somewhat surprised that the people in charge of this Rock Paper Scissors tournament chose a single-elimination format. Better to use some form of Condorcet's method, if we wish to avoid Condorcet's paradox, of which Paper Scissors Rock is but one example.

UPDATE: Dammit, I hate blogging. Immediately after I wrote this post, I went over to the Volokh Conspiracy and noticed the very same picture. Early bird catches the worm, I guess.

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Yeah, you guys both beat me

Yeah, you guys both beat me to this one. Dammit.

But I may still do a lenghthy game-theoretic analysis of rock-paper-scissors -- because, come on, who ever gets enough of pointless academic excercises?