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Subject: Re: A question about statistics...

Author: Peter Berger

Date: 16:51:15 01/04/04

Go up one level in this thread

On January 04, 2004 at 19:46:51, Ricardo Gibert wrote:

>On January 04, 2004 at 17:44:08, Dieter Buerssner wrote:
>>On January 04, 2004 at 13:46:48, Ricardo Gibert wrote:
>>>On January 04, 2004 at 12:47:25, Peter Berger wrote:
>>>>On January 04, 2004 at 12:40:00, Ricardo Gibert wrote:
>>>>>On January 04, 2004 at 12:29:15, Mark Young wrote:
>>>>>>A score of 17 - 3 in a 20 game match has a certainty of over 99% that the winner
>>>>>>of the match is stronger then the loser.
>>>>>>A 100 game match ending 55 - 45 only has a 81% chance that the winner of the
>>>>>>match is the stronger program.
>>>>>>A 200 game match ending 106 - 94 only has a 78 % chance that the winner is
>>>>>>stronger then the loser.
>>>>>Nothing you have said is really correct because you have ignored the significant
>>>>>effect of draws in a match.
>>I think, I understand the issue you rise. However, 17-3 will be more significant
>>than the other results independent of draw. So, still some truth there. I really
>>wonder, how exactly Elostat calculates the +/- margins to the calculated rating.
>>Does anybody know an URL, where one can read this?
>>>>The percentage of draws doesn't matter at all when it is about the conclusion
>>>>which program is strongest based on the above match results.
>>>>This has been shown by Remi Coloum and explained in multiple posts
>>>>here(unfortunately the search engine hasn't found a new home yet).
>>>>6-0 with 0 draws and 6-0 with 1000 draws has the exact same prediction value
>>>>when it is about the question which engine is stronger based on a match result.
>>>In this case, the number of decisive games (w+L=6) and margin of victory (w-L=6)
>>>is the same in both cases so the conclusion they have equal value is correct.
>>>    -------------------------------
>>>In the examples given before, the number of decisive games depends on the number
>>>of draws e.g. +17-3=0 and +14-0=6 are not of equal value since the number
>>>decisive games are not equal.
>>Hey, I think Peter and Ricardo wanted to say exactly the same thing. Still they
>>succeeded to disagree.
>??? Not exactly the same thing at all. He said, "The percentage of draws doesn't
>matter at all when it is about the conclusion which program is strongest based
>on the above match results." This implies that +55-45=0 is the same as +10-0=90
>and I completely disagree with this.

Dieter wasn't that wrong. My answer was non-sequitur and worded in a superficial
way, which is a bad thing. Though you are right and my post made little sense I
didn't really disagree with you anyway.

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