Author: Uri Blass
Date: 01:35:17 01/10/03
Go up one level in this thread
On January 10, 2003 at 04:05:30, Bas Hamstra wrote:
>On January 09, 2003 at 10:18:23, Uri Blass wrote:
>
>>After I make a move of a white pawn I need to change only part of the bitboard
>>of the pawns.
>>
>>Is there a more efficient way to do it then things like?
>>
>>if (side==LIGHT)
>>{
>> pawnattacksAH[LIGHT]=(pawnBB[LIGHT]<<9)&NOTFILEABB;
>> pawnattacksHA[LIGHT]=(pawnBB[LIGHT]<<7)&NOTFILEHBB;
>>...
>>}
>>else
>>{
>> pawnattacksAH[DARK]=(pawnBB[DARK]>>7)&NOTFILEABB;
>>...
>>}
>>
>>I remember that GCP told me that I can get the information from hash tables.
>>
>>Updating pawnBB after every make move that change the pawn structure is cheap so
>>I do it but I wonder how can I get the information from hash tables when I do
>>not want to use static scores for pawn structure but to use other information in
>>the board to evaluate pawn structure.
>>
>>Should I start with doing it without caring about speed and only later care
>>about storing the information that I need in hash tables?
>>
>>The information that I want first is squares of the passed pawns that are
>>protected by pawns and square of the weak pawns of both sides.
>>
>>There is another information that today I remember without bitboard(number of
>>pawns in every file)
>>
>>Should I change the way that I remember it to bitboard and if yes how to do it?
>>
>>Uri
>
>Since you will probably evaluate each pawn anyway, you can keep counters of
>pawns at every file. I do that (and I use rotated bitboards). I store an 3
>character arrays in my pawnhashtable: WPawnsOnFile[8] BPawnsOnFile[8] and
>KingSafety[8]. If white castled short and black long, KingSafety[1] will give me
>white's kingsafety and KingSafety[6] gives black's KingSafety.
>
>Bas.
I do not understand what does king safety in your pawn hash tables.
I also do not understand your example
KingSafety[1] is for the king in g1 so my first thought is that it is relevant
for the g file.
If I assume that h file is 0 and g file is 1 then in this case c file is 5 and
not 6.
Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.