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Subject: Re: Yace 0.99.56 still the strongest amateur engine!? (Crafty 9.)

Author: Dann Corbit

Date: 22:10:12 09/06/02

Go up one level in this thread


One point to consider is that 90% correct move choices means certain failure
within only a few plies.

First ply :9/10 chance that the program makes the best move.

Second ply will only be correct IF the first ply was also correct.  If the first
move chosen was bad, then this is still bad.  So we multiply the probabilities
since the events are dependent.  Hence 9*9/(10*10) = .81 chance

3rd: .729 chance we are OK so far, if the program guesses right 90% of the time

4th: 0.6561

5th: 0.59049

6th: 0.531441

7th: 0.4782969

8th: 0.43046721

9th: 0.387420489

10th: 0.3486784401 ... by now the chance is about 1/3 that we have not made a
blunder with an engine that guesses right 90% of the time.  By move 20 the odds
are 0.12157665459056928801 and by move 30 we are down to 4% chance.

So it is clear that a program that almost always guesses right is almost certain
to fail very early in the game!

In short, I think both you and Uri are correct, but are saying different things.





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