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Subject: Re: Bug in craftys movegenerator?

Author: Uri Blass

Date: 05:50:38 07/10/03

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On July 10, 2003 at 08:26:08, Michel Langeveld wrote:

>On July 10, 2003 at 06:56:10, Mikael Bäckman wrote:
>
>>Hi,
>>
>>I've been tracking down problems with my engine, and found some oddities in
>>updatíng the hashsignature after each move. Anyways, I thought "I wonder how
>>crafty does it" and well, I think crafty does it wrong.
>>
>>Code from Crafty 19.3:
>>
>>  case king:
>>    if (wtm) {
>>      [snip]
>>->    if (WhiteCastle(ply) > 0) {     <-
>>        if (WhiteCastle(ply+1)&2) HashCastleW(1,HashKey);
>>        if (WhiteCastle(ply+1)&1) HashCastleW(0,HashKey);
>>        [snip]
>>      }
>>    }
>>    else {
>>      [snip]
>>->    if (BlackCastle(ply+1) > 0) {   <- not the same ply as above?
>>        if (BlackCastle(ply+1)&2) HashCastleB(1,HashKey);
>>        if (BlackCastle(ply+1)&1) HashCastleB(0,HashKey);
>>        [snip]
>>      }
>>    }
>>    break;
>>
>>Since crafty knows how to castle the code obviously works, but it doesn't look
>>right..
>>
>>Regards,
>>Mikael
<snipped>
>Since blackcastling rights only change by black moves ...

Not correct.

If I capture your rook then you will not be able to castle with the missing
rook.

Uri



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