Author: Simon Finn
Date: 11:09:37 09/30/01
Go up one level in this thread
On September 30, 2001 at 09:49:15, Simon Finn wrote:
>On September 30, 2001 at 04:27:44, Uri Blass wrote:
>
>>On September 29, 2001 at 21:05:58, allan johnson wrote:
>>
>>>On September 29, 2001 at 18:02:31, Uri Blass wrote:
>>>
>>>>PATZER 3.61 - Quark
>>>>[D]8/6kB/8/6P1/P7/4p3/3bK3/8 w - - 0 1
>>>>
>>>>I wonder what is the reason that patzer evaluated
>>>>this drawn position as +2.50 for white.
>>>>
>>>>Even programs with only material evaluation can see only +1
>>>>for white.
>>>>
>>>>What is the reason for 1.5 pawns positional bonus?
>>>>
>>>>Uri
>>> Uri: Perhaps the programmer did not include rules about end games when the
>>>bishops are on opposite colours?
>>>Al
>>
>>even without rules for opposite bishop the question still remain
>>What is the reason for 1.5 pawns positional bonus.
>>
>>I do not think that a dustance passed pawn justifies 1.5 pawn positional bonus.
>
>Move the other White pawn from g5 to g4:
>
>[D]8/6kB/8/8/P5P1/4p3/3bK3/8 w - - 0 1
>
>Now White appears to be winning after (for example)
>
>1. Be4 Kf6 2. Kd3 Ke5 3. Bf3 Kd6 4. Kc4 Kc7 5. Kb5 Bc3 6. a5 etc.
4... Ba5 5. Kb5 Bc3 6. a5 Bd4 7. Kc4 Ba7 8. Kd3 Ke5 may well be a draw.
So White should play 4. Kd4! with zugzwang (I think), for example:
4. Kd4 Kc7 5. Kc5 Bc3 6. Kc4 Ba5 7. Kb5 Bc3 8. a5 Bd4 9. Kc4 Ba7 10. Kd5
7... Bb6 8. g5 Bd4 9. Kc4 Bg7 10. a5
Black can finesse with
1. Be4 Kf6 2. Kd3 Ke6 3. Bf3 Ke5
but then White can counter-finesse with 4. Kc4!, for example:
4. Kc4 Be1 (4... Kd6 5. Kd4!) 5. Kb5 Kd6 6. a5 Kc7 (6... Bc3 7. Kb6) 7. a6 etc
Simon
>
>I guess that it's very difficult to write an evaluation function that recognises
>the key difference between the two positions (the White pawn is too vulnerable
>on g5).
>
>Simon
>
>
>
>
>
>
>>
>>Uri
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