Author: Tony Werten
Date: 01:55:14 11/27/01
Go up one level in this thread
On November 26, 2001 at 17:55:23, Michel Langeveld wrote:
>On November 25, 2001 at 15:07:16, Tony Werten wrote:
>
>>On November 25, 2001 at 11:30:51, Michel Langeveld wrote:
>>
>>>Fixed some errors in the passer code...
>>>
>>> //grouping rule
>>> //isolated pawns
>>> //passers
>>> //double and triple pawns
>>> bool whiteGroup = false;
>>> bool blackGroup = false;
>>> int whiteGroups = 0;
>>> int blackGroups = 0;
>>> bool whiteIsolated = false;
>>> bool blackIsolated = false;
>>>
>>> for (int i=0; i<8; i++)
>>> {
>>> if (evalStructure.whitePawnsPlace[i] > 0)
>>> {
>>>
>>> //double pawns
>>> if (evalStructure.whitePawnsPlace[i] == 2)
>>> {
>>> score -= PAWNDOUBLE_PENALTY;
>>> }
>>> if (evalStructure.whitePawnsPlace[i] == 3)
>>> {
>>> score -= PAWNTRIPLE_PENALTY;
>>> }
>>>
>>> //passer?
>>> if (evalStructure.blackPawnsPlace[i] == 0)
>>> {
>>> if (
>>> (i != 0 &&
>>> evalStructure.blackPawnsPlace[i-1] == 0 &&
>>
>>connected passed pawns don't pass this test
>>
>>> evalStructure.whitePawnsPlace[i-1] > 0 &&
>>> evalStructure.blackPawnsPlace[i-2] == 0) ||
>>
>>How are passed pawns and not having a pawn 2 files away related ? BTW i-2 can
>>become -1 here, hope your array runs from -1 to 8.
>
>I also evaluate pawns 2 further than the current pawn because I had big problems
>with evaluation the following pawn structure.
>
> 8/pppp4/8/8/8/8/P1PP4/8 w - - 0 1
>
>How many passed pawns does white have....?
0
White has a passed pawn when: (board seen from white)
white has a pawn on current line
AND
(black does not have a pawn on current line OR *1
blackpawn_rank[current_line] < whitepawn_rank[current_line]) *1
AND
(current_line=0 OR
black does have pawn on [current_line-1] OR
blackpawn_rank[current_line-1]<=whitepawn_rank[current_line])
AND
(current_line=7 OR
black does have pawn on [current_line+1] OR
blackpawn_rank[current_line+1]<=whitepawn_rank[current_line])
In your diagram none of the 3 pawns pass *1
>
>p.s.1 yes there's a bounce problem in my code. I programmed it in by purpose to
>gain some extra speed. But fixed it later again.
>p.s.2 I'm not sure what you meant by the connected passed pawns comment. Can you
>give an example?
I'm not sure how many passed pawns your evaluation finds here.
[D] 7k/8/8/8/8/8/2PP4/7K w - - 0 1
Tony
>
>Thanks for your comments.
>
>Regards,
>
>Michel
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