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in reply to Re: Re: (OT) Meditate on this brain-teaser
in thread (OT) Meditate on this brain-teaser

Tut, tut Dragonchild,

There are a lot of assumptions being made here: That the players are rational thinkers and intelligent enough to realise this kind of strategy etc... I just find these problems incredibly annoying because I'm not very good at them and people who get the answer right tend to do so not because of induction but more because they've seen it before! It rather reminds me of a physics joke I once heard.

A horseracing fan wins a million dollars/pound/shekels in the lottery and decides to invest it in an interesting proposition: He will find out how to predict the winner of a horserace with 95% accuracy based on the build, weight and past form of a horse. To do this he goes to a racehorse trainer, a molecular biologist and a theoretical physicist: He gives them each $10000 just for working for one year and promises the winner $250,000 more if they win.

After the year is up he returns to each. The horse trainer is pleased to report than he can get it right 75% of the time and the fan is impressed, but his heart heavy he wanders on. The molecular biologist is delighted to report that he got to 80% but progressed no further. Eventually the fan comes to the physicist, who replies, "Yes, I can predict which horse will win any race with 99.5% probability of success with one minor catch."

Needless to say, the racing fan is impressed and offers the physicist the prize money in return for the analysis, however the physicist being an honest man says he must tell him the catch first:"It must be a spherical horse running in a vacuum!"

"A nerd is someone who knows the difference between a compiled and an interpreted language, whereas a geek is a person who can explain it cogently over a couple of beers"
       - Elgon

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Re4: (OT) Meditate on this brain-teaser
by dragonchild (Archbishop) on Dec 12, 2001 at 23:05 UTC
    Those are cogent issues with this type of brainteaser. However, it is a common assumption for the brainteaser that all subjects are intelligent and rational.

    The idea isn't to find the real-world solution, but to find the correct solution (for some value of correct).

    I guess the way I think about it is that a chess GM can say "Mate in 8 moves." Ok, that's great. However, it's mate in 3 moves unless your opponent does the perfectly correct move. The GM has to assume perfect play when making that assertion, not normal play.

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