Author: Christophe Theron
Date: 12:45:28 06/13/00
Go up one level in this thread
On June 13, 2000 at 08:36:24, Oliver Roese wrote:
>On June 12, 2000 at 05:46:59, Rémi Coulom wrote:
>
>>On June 10, 2000 at 13:44:35, blass uri wrote:
>>
>>>On June 10, 2000 at 11:54:17, Ed Schröder wrote:
>>>
>>[...]
>>>>
>>>>Maybe the opposite is true. It depends per program how the programmer
>>>>looks at things. For this position I would say that having 2 outside
>>>>passers usually is a great advantage and as such is rewarded by a chess
>>>>program. If so then this position is an exception to the rule. And the
>>>>end-game is full of exceptions much more than the mid-game.
>>>>
>>>>Ed
>>>
>>>Having 2 outsides passed pawns is an advantage but having 2 advanced passed pawn
>>>is also an advantage.
>>>
>>>The problem is to know which advantage is bigger.
>>>
>>>I agree that it is not a simple problem and I understand the fact that
>>>programmers prefer to waste more time about other problems.
>>>
>>>I still believe that it is possible to see it at evaluation time by an array
>>>64*64*64 of distance to promotion.
>>
>>You are perfectly right about this idea. I do it in TCB. I have a table for
>>distance to promotion for KPK and PPK. In fact, it is not really a table of
>>distance to promotion, but a table that gives the maximum number of "not a King
>>move by the opponent" before the pawn is promoted. I call it "extended square of
>>the King". It is not in the latest version of TCB. I will make it available in
>>the next version. If programmers are interested in the code to generate the
>>table, I will send it to them.
>>
>>PPK is nice, but KPK is probably much more useful. TCB can solve WAC #100 in 25
>>seconds or so on a celeron 400 thanks to it. It saves 3 or 4 plies as compared
>>to the standard "square of the Pawn" rule (or is it "square of the King"?). It
>>is also very good at detecting that a pawn can win a tempo by checking the
>>opponent on its way to promotion.
>>
>>I do not think it would solve this position though. I am not a good chess
>>player, but the position after the Queen exchange seems unclear to me. Black can
>>promote first, but White will promote on the next half move. Is it a winning
>>advantage? Or I might be missing something. I will try it on TCB when I am back
>>home.
>>
>>Greetings,
>>Remi
>
>Here is a human-like approach:
>Apply the rule of the "wandering square". I got it from Awerbachs book about
>pawnendings:
>
>[D]8/8/1k6/8/P2P4/8/8/K7 w - - 0 1
>
>In the above diagram the two white pawns are on the corners of a square
>(a4-d4-a7-d7). The rule say, that the two pawns are unstoppable by the opposite
>king, if their common square has reached the edge of the board.
>Since this is not the case, here black has hope to stop the pawns. (He will hold
>the draw with 1..Ka5).
>
>[D]Q3q3/4k3/8/5p2/2p5/8/P6P/4K3 w - - 0 1
>This position is from blass uri.
>According to the rule the white pawns are unstoppable.
>But the blacks pawns are unstoppable to, after the unavoidable ...f4.
>Since we have no dumb advice here, a search is required. It reveals, that black
>wins after 1.Qxe8+ but he is only up a tempo.
>
>Oliver Roese
Your rule is interesting, but I have a hard time believing that it holds when
the pawns are on their original square. A pawn on its original square can move
two squares up (or down), and that should imply a special case for your rule,
isn't it?
Christophe
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