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Subject: Re: why is the evaluation function of computers(passed pawns) so silly?

Author: blass uri

Date: 09:08:58 07/16/98

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On July 16, 1998 at 10:35:17, Dan Homan wrote:

>On July 15, 1998 at 07:35:10, blass uri wrote:
>
>>
>>On July 14, 1998 at 11:59:33, blass uri wrote:
>>
>>>the position
>>>7r/1k2P2P/4p3/1pp5/8/2pp4/1n3PP1/R4K1R
>>>white to play
>>>white should play g4
>>>but computers like e8=Queen Rxe8 h8=Queen Rxh8 Rxh8 and
>>>I think that black is winning instead of losing
>>>
>>>can a computer program find g4 in a reasonable time
>>>or all of them are stupid and do not understand that the white pawns h7 g6 are
>>>stronger than a rook
>>>
>>>Uri
>>Junior needed near 10 hours to find g4
>>I think fritz is not better
>>computer programs do not understand that knight and passed pawns are
>>better than a 2 rooks
>>
>
>Here is the output of my amateur program, EXchess.  It finds g4 in about
>6 seconds on a slow machine. Although the score stays negative for quite
>some time, it does steadily increase.  I have put very little work into the
>passed pawn code, so I am not sure if finding this move is more than just
>dumb luck.
>
>  - Dan
>
>White-To-Move[1]: setboard 7r/1k2P2P/4p3/1pp5/8/2pp4/1n3PP1/R4K1R w
>White-To-Move[1]: display
>
>  +---+---+---+---+---+---+---+---+
>8 |   |   |   |   |   |   |   ||    White to move
>  +---+---+---+---+---+---+---+---+
>7 |   ||   |   | P |   |   | P |    castle: -
>  +---+---+---+---+---+---+---+---+
>6 |   |   |   |   ||   |   |   |
>  +---+---+---+---+---+---+---+---+
>5 |   |||   |   |   |   |   |
>  +---+---+---+---+---+---+---+---+
>4 |   |   |   |   |   |   |   |   |    fifty: 0
>  +---+---+---+---+---+---+---+---+
>3 |   |   |||   |   |   |   |    Computer time: 30 seconds
>  +---+---+---+---+---+---+---+---+
>2 |   ||   |   |   | P | P |   |
>  +---+---+---+---+---+---+---+---+
>1 | R |   |   |   |   | K |   | R |
>  +---+---+---+---+---+---+---+---+
>    a   b   c   d   e   f   g   h
>
>White-To-Move[1]: analyze
>Analysis mode: Enter commands/moves as ready.
>
>  1.   ++       0        2   1. e8=Q
>  1.   -556     0       14   1. g3
>  1.   -499     0       15   1. g4
>  1.   -499     0       36   1. g4
>  2.   --
>  2.   -546     0      425   1. g4 b4
>  2.   -540     0      706   1. Re1 Kc6
>  2.   -540     0      763   1. Re1 Kc6
>  3.   ++       0      859   1. Re1
>  3.   -493     0     1163   1. e8=Q Rxe8 2. h8=Q
>  3.   -493     1     2173   1. e8=Q Rxe8 2. h8=Q
>  4.   ++       1     2343   1. e8=Q
>  4.   -468     1     2463   1. e8=Q Rxe8 2. Ra7+ Kxa7
>  4.   -453     1    10558   1. Ra3 c2 2. Rc3 Kc6 3. g4
>  4.   -453     1    12178   1. Ra3 c2 2. Rc3 Kc6 3. g4
>  5.   -477     1    17598   1. e8=Q Rxe8 2. Ra8 Rxa8
>  5.   -476     1    24848   1. Rh3 b4 2. e8=Q Rxe8 3. Ra7+ Kxa7
>  5.   -444     2    35082   1. g4 b4 2. e8=Q Rxe8 3. Ra7+ Kxa7
>  5.   -443     2    43613   1. Rh4 b4 2. e8=Q Rxe8 3. Ra7+ Kxa7
>  5.   -442     2    53415   1. Kg1 d2 2. e8=Q Rxe8 3. Ra7+ Kxa7
>  5.   -442     2    58118   1. Kg1 d2 2. e8=Q Rxe8 3. Ra7+ Kxa7
>  6.   -459     3    97429   1. Rc1 d2 2. Ra1 d1=Q+ 3. Rxd1 Nxd1 4. Ke2 Nb2
>  6.   -448     5   156222   1. Rh3 b4 2. Rh4 Kb8 3. e8=Q+ Rxe8 4. Ra8+ Kxa8
>  6.   ++       6   194502   1. g4
>  6.   -409     7   227112   1. g4 Nc4 2. e8=Q Rxe8 3. h8=Q Rxh8
>  6.   -409     8   289357   1. g4 Nc4 2. e8=Q Rxe8 3. h8=Q Rxh8
>  7.   -406    13   447301   1. g4 b4 2. g5 Kb6 3. e8=Q Rxe8 4. h8=Q Rxh8
>  7.   -406    20   705727   1. g4 b4 2. g5 Kb6 3. e8=Q Rxe8 4. h8=Q Rxh8
>  8.   -383    47  1628965   1. g4 Nc4 2. Rh3 Nd2+ 3. Ke1 c4 4. e8=Q Rxe8
>                             5. h8=Q Rxh8
>  8.   -383   130  4602417   1. g4 Nc4 2. Rh3 Nd2+ 3. Ke1 c4 4. e8=Q Rxe8
>                             5. h8=Q Rxh8
>  9.   ++     149  5327119   1. g4
>  9.   --
>  9.   -336   773 28096190   1. g4 c2 2. e8=Q Rxe8 3. h8=Q Rxh8 4. Rxh8 Kc6
>                             5. Ra6+ Kd5 6. g5
>  9.   -336   773 28124503   1. g4 c2 2. e8=Q Rxe8 3. h8=Q Rxh8 4. Rxh8 Kc6
>                             5. Ra6+ Kd5 6. g5
> 10.   -315  1196 43034481   1. g4 c2 2. e8=Q Rxe8 3. h8=Q Rxh8 4. Rxh8 b4
>                             5. Ke1 Kc6
> 10.   -315  1868 68186566   1. g4 c2 2. e8=Q Rxe8 3. h8=Q Rxh8 4. Rxh8 b4
>                             5. Ke1 Kc6
> 11.   ++    2838 102232936   1. g4
> 11.   -259  5603 205077307   1. g4 Nc4 2. Rh3 Nd2+ 3. Kg2 c4 4. Rh5 c2
>                             5. Rg5 b4 6. Rg8 c1=Q 7. Rxc1 Rxh7
> 11.   -259  5785 212303465   1. g4 Nc4 2. Rh3 Nd2+ 3. Kg2 c4 4. Rh5 c2
>                             5. Rg5 b4 6. Rg8 c1=Q 7. Rxc1 Rxh7
>
>
>>I believe that most of humans with 2000 elo will not miss g4
>>
>>Uri
how did you get negative evaluation?
if you count material white has the advantage

my programs has positive evaluation after e8=Q because they evaluate 2 rooks as
better than knight and advanced passed pawns.

Uri



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