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Subject: Re: Doctor 3 avoided axb6

Author: Robert Hyatt

Date: 07:35:15 08/17/99

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On August 17, 1999 at 03:46:23, blass uri wrote:

>
>On August 17, 1999 at 02:14:10, Ed Schröder wrote:
>
>>On August 16, 1999 at 23:55:49, Robert Hyatt wrote:
>>
>>>On August 16, 1999 at 14:25:47, blass uri wrote:
>>>
>>>>
>>>>On August 16, 1999 at 12:59:10, Ed Schröder wrote:
>>>>
>>>>
>>>>>But in the end the human knows how to play chess. A computer will never
>>>>>find moves like Ra1 (Fischer) or Rxd4 (Kasparov) and and and... Ok, maybe
>>>>>in 100 years :-) Just try this (old and simple) one.
>>>>>
>>>>>5rk1/5p2/pr2pPp1/Pp1pP1Pp/1PpP3P/K1P5/8/8 w - - am a5b6;
>>>>
>>>>Doctor3 after 16 minutes and 42 seconds on p200MMX:
>>>>
>>>>Kb2 44/45 with evaluation -10.51
>>>>
>>>>Uri
>>>
>>>
>>>takes crafty on my PII/300 notebook 1:32 to find Kb2.  Takes my quad xeon
>>>about 12 seconds.  Here is PII/300 output:
>>>
>>>               18->  12.18  -8.14   1. axb6 Rb8 2. Kb2 Rxb6 3. Kc2 a5 4.
>>>                                    bxa5 Ra6 5. Kb2 Rxa5 6. Kb1 Ra3 7.
>>>                                    Kb2 b4 8. cxb4 Rd3 9. b5 Rxd4
>>>               19    18.89  -8.20   1. axb6 Rb8 2. Kb2 Rxb6 3. Kc2 a5 4.
>>>                                    bxa5 Ra6 5. Kb2 Rxa5 6. Kb1 Kf8 7.
>>>                                    Kb2 Ra4 8. Kb1 b4 9. cxb4 Rxb4+ 10.
>>>                                    Kc2 Ke8
>>>               19->  19.09  -8.20   1. axb6 Rb8 2. Kb2 Rxb6 3. Kc2 a5 4.
>>>                                    bxa5 Ra6 5. Kb2 Rxa5 6. Kb1 Kf8 7.
>>>                                    Kb2 Ra4 8. Kb1 b4 9. cxb4 Rxb4+ 10.
>>>                                    Kc2 Ke8
>>>               20    20.22     --   1. axb6
>>>               20    31.67  -9.25   1. axb6 Rb8 2. Kb2 Rxb6 3. Kc2 a5 4.
>>>                                    bxa5 Ra6 5. Kb2 Rxa5 6. Kb1 Ra3 7.
>>>                                    Kb2 b4 8. cxb4 Rh3 9. Kc2 Rxh4 10.
>>>                                    Kd2 Rxd4+ 11. Ke3
>>>               20     1:32  -8.62   1. Kb2 Rfb8 2. Kc2 Kf8 3. Kd2 Ke8 4.
>>>                                    Ke3 R6b7 5. Kd2 Ra8 6. Ke3 Kd7 7. Kf4
>>>                                    Rc8 8. Ke3 Kc6 9. Kf4 Rd7 10. Ke3 Rcc7
>>>               20->   1:32  -8.62   1. Kb2 Rfb8 2. Kc2 Kf8 3. Kd2 Ke8 4.
>>>                                    Ke3 R6b7 5. Kd2 Ra8 6. Ke3 Kd7 7. Kf4
>>>                                    Rc8 8. Ke3 Kc6 9. Kf4 Rd7 10. Ke3 Rcc7
>>>               21     2:32  -8.62   1. Kb2 Rfb8 2. Kc2 Kf8 3. Kd2 Ke8 4.
>>>                                    Ke3 R6b7 5. Kd2 Ra8 6. Ke3 Kd7 7. Kf4
>>>                                    Rbb8 8. Kg3 Re8 9. Kf4 Rad8 10. Ke3
>>>                                    Rc8 11. Kf4
>>>               21->   2:32  -8.62   1. Kb2 Rfb8 2. Kc2 Kf8 3. Kd2 Ke8 4.
>>>                                    Ke3 R6b7 5. Kd2 Ra8 6. Ke3 Kd7 7. Kf4
>>>                                    Rbb8 8. Kg3 Re8 9. Kf4 Rad8 10. Ke3
>>>                                    Rc8 11. Kf4
>>
>>That's all nice of course but the score isn't 0.00 as it should be which
>>was my point of computers and understanding chess. Every 1500 player
>>sees it is a draw as long as you don't capture except computers.
>>
>>A 100 years before computers will recognize this kind of positions as
>>a draw?
>>
>>Ed Schroder
>
>I am more optimistic
>I do not think we need to wait 100 years for it.
>
>It is not a problem to do a program that evaluate it as a draw today.
>
>One way is to tell the computer that if all the 8 pawns are blocked in different
>files and one side has only pieces behind the pawns that are only rooks or a
>bishop that cannot take the pawn then the position is a draw.
>
>Programmers prefer not to do it because it cannot help much in games.
>
>Uri


This is a well-known problem.  Cray Blitz solved this position in 1984 when
no one thought a computer could.  It was very fast, of course.  This was a
demo position at ACC4, in a paper called "Artificial Stupidity".  I bet the
presenter that CB would not take and he said "baloney".  He got to put that
on two pieces of bread and had a sandwich for dinner.  :)

It is a non-trivial, but fixable problem.  But the fix will hurt because it
won't be 'free'...



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