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Subject: Re: Test position: draw

Author: Uri Blass

Date: 22:44:40 10/25/03

Go up one level in this thread


On October 26, 2003 at 01:43:45, Uri Blass wrote:

>On October 26, 2003 at 01:03:53, scott farrell wrote:
>
>>On October 24, 2003 at 20:35:33, José Carlos wrote:
>>
>>>  From a test game of my engine Anubis:
>>>
>>>[D]r1b5/pp1p3k/1b1p4/5R2/4PB2/2N4r/PP3n1P/1K4R1 b - - 7 30
>>>
>>>  It seems that only Nd3 draw, according to Ruffian. My program lost this game
>>>(with black). It seems very hard for it to find the drawing move (it wants to
>>>play Kh8 for a long time), although I believe most programs will find it easier.
>>>  What do your engines say? Do other moves also draw?
>>>
>>>  José C.
>>It mostly depends on how you score a draw.
>>
>>Crafty eventually says Nd3 also with a draw score.
>>
>>My engine chompster sees white attempting a draw due to contempt factor, and
>>+0.5 for white as a draw, with black playing Bd4 - and black cant stop a forced
>>draw by white - which with contempt factor says its a win to white that black
>>cant stop. This is good if the player on white has less rating, which is the
>>idea of the contempt fator, they will probably just go for the draw (as I would
>>against a comp).
>>
>>This probably means a few moves before this my engine may have avoided this
>>position given it was heading towards a draw.
>>
>>your positional scores for the bad bishop and bad rook vs more material for
>>black will have a huge effect on whether it keeps or discards branches with
>>draws in them.
>>
>>playing with my contempt factor, it sees ND3, or Bd4 - it really depends who its
>>thinks is ahead, and which player might be trying for a draw, given wither side
>>can force a draw (and for a bit Nxe4 as a draw, but then sees white wins on the
>>next ply).
>>
>>Scott
>
>Movei see Nxe4 with a draw score at small depth and only at depth 13 it fails
>low and changes its mind to Nd3
>
>depth=13 -0.52 f2d3
>Nodes: 38514650 NPS: 194833
>Time: 00:03:17.68
>depth=14 +0.00 f2d3 f5f7 h7h8 f7f8 h8h7 f8f7
>Nodes: 50914975 NPS: 193924
>Time: 00:04:22.55
>depth=15 +0.00 f2d3 f5f7 h7h8 f7f8 h8h7 f8f7
>Nodes: 64021743 NPS: 196989
>Time: 00:05:25.00
>
>After Nxe4
>It says
>
>depth=12 +0.01 g1g2
>Nodes: 14464477 NPS: 204966
>depth=12 +0.30 g1g2
>Nodes: 19145211 NPS: 195618
>Time: 00:01:37.87
>depth=12 +0.61 g1g2 e4c3 b2c3 b6a5 f5a5 b7b6 a5g5 c8b7 g2e2 h7h8 f4d6 a8g8 g5g8
>h8g8 b1c2
>Nodes: 34670678 NPS: 186813
>Time: 00:03:05.59
>
>After Kh8 it is more easy for it to find a clear positive score for white and
>after some time it finds a clearly winning score.
>
>depth=11 +0.62 c3d5 f2e4 f5f8 h8h7 f8f7 h7h8 d5b6 a7b6 f7f8 h8h7 f8g8 h3g3 g8g3
>e4g3 g1g3 d6d5
>Nodes: 3643839 NPS: 206684
>Time: 00:00:17.63
>
>depth=11 +0.62 c3d5 f2e4 f5f8 h8h7 f8f7 h7h8 d5b6 a7b6 f7f8 h8h7 f8g8 h3g3 g8g3
>e4g3 g1g3 d6d5
>Nodes: 9805659 NPS: 205698
>Time: 00:00:47.67
>
>depth=12 +4.74 c3d5 f2e4 g1g4 b6d8 f5f8 h8h7 f8g8 e4g5 g8d8 h3f3 f4g5 f3f1 g5c1
>b7b5 h2h4
>Nodes: 71760374 NPS: 185345
>Time: 00:06:27.17
>
>After Bd4 again it is eady to see a big positive score for white
>
>depth=9 +0.56 c3b5 d4b2 b1b2 f2d3 b2a1 d3f4 f5f4 d6d5 f4f7 h7h8 f7f8 h8h7 e4d5
>h3h2 f8f7 h7h8
>Nodes: 1329410 NPS: 199911
>Time: 00:00:06.65
>
>depth=11 +1.46 c3b5
>Nodes: 8632764 NPS: 185571
>Time: 00:00:46.52
>
>depth=11 +1.59 c3b5 d4b2 b1b2 f2d3 b2b1 d3f4 f5f7 h7h8 f7f4 d6d5 f4f8 h8h7 g1g8
>h3h6 f8c8 a8c8 g8c8 d5e4
>Nodes: 10837503 NPS: 186499
>Time: 00:00:58.11
>depth=12 +2.10 c3b5 b7b6 b5d4 c8b7 f5f7 h7h8 f4d6 b7e4 b1a1 f2d3 d6e7 h3h6 e7f6
>h6f6 f7f6 d7d5 f6h6 e4h7
>Nodes: 25054356 NPS: 184304
>Time: 00:02:15.94
>
>Uri

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