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Subject: Re: The Code for the Rybka-Mate-Bug

Author: Vasik Rajlich

Date: 05:00:00 12/14/05

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On December 14, 2005 at 04:44:15, Steve Maughan wrote:

>Vasik,
>
>>The problem is when the hash entry ages.
>
>This is easy to get around - just store the distance to mate from the *position*
>(i.e. not the root) in the hash table.
>
>In pseudo code:
>
>procedure push_hash(position)
>begin
>	if winning_mate_value_in_hash then
>		hash_draft_depth += position's_ply_from_root
>	else if losing_mate_value_in_hash then
>		hash_draft_depth -= position's_ply_from_root
>	store(position)
>end;
>
>procedure probe_hash(position)
>begin
>	if found_in_table(poistion) then
>	begin
>		get_hash(position)
>		if winning_mate_value_in_hash then
>			hash_draft_depth -= position's_ply_from_root
>		else if losing_mate_value_in_hash then
>			hash_draft_depth += position's_ply_from_root
>	end
>end;
>
>I hope this helps!
>
>Regards,
>
>Steve

Steve,

thanks, I guess this also works - although it's a bit dirty.

Vas



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