Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: King danger extensions

Author: Ulrich Tuerke

Date: 00:30:47 02/18/99

Go up one level in this thread


On February 17, 1999 at 14:50:24, James Robertson wrote:

>On February 17, 1999 at 03:56:17, Ulrich Tuerke wrote:
>
>>
>>On February 16, 1999 at 16:26:53, James Robertson wrote:
>>
>>>My program keeps falling prey to king attacks. Although it does very well
>>>tactically when it's king is not threatened, it frequently plays combinations
>>>that win material (it thinks), only to find, say, a back-rank mate that went
>>>unnoticed. I am using a one-reply-to-check extension, the mate extension after
>>>null move, and extending half a ply whenever there is a check in the tree. No
>>>check detection is done in the q-search. Are there any other standard check
>>>extensions I am not doing?
>>>
>>>James
>>
>>I have had similar problems regarding blindness for back-rank mates. I tried to
>>solve it this way: my the static evaluation determines if a king is on a weak
>>back rank (e.g only escape squares to same rank and neither friendly rook nor
>>friendly queen on the back rank to protect, ...). In this case the ecaluation
>>sets a flag, which controls the move generation of the queiscence in order to
>>also generate checking moves wth queen and rook to unprotected squares on the
>>weaked back rank ; seems to help and doesn't cost too much, if you do this only
>>close to the last full search ply.
>>
>>Uli
>
>This is an interesting suggestion; I'll try it out.
>
>James

What I forgot to mention: in those cases where you have generated these checking
moves, you have to verify it it's a mate.

Uli



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.