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Subject: Re: null move and mate threat

Author: Michael Henderson

Date: 16:15:02 10/08/04

Go up one level in this thread

On October 08, 2004 at 18:43:04, Stuart Cracraft wrote:

>Okay so on the one hand I am supposed to do a reduced
>search for null move with bounds -beta,-beta+1, and
>return if the value is >= beta.
>
>The mate threat has to be compared with a mate value
>but the beta's above aren't relevant. Do I need to
>do a second reduced search after the above with bounds
>-MATE,-MATE+1 and see if it is >= MATE and if so set
>the mate threat flag to trigger the extension???

Hi Stuart,

No second search is needed.  If you get a -MATE in 1 value (or whatever) as a
fail low, then you extend.  However, if you use bounded mate scores in the hash
table, this does not work because it is not possible to get exact mate scores.
This is why I am giving up using it.

Could you please explain/post code for how you store/retrieve mate scores in the
hash table?  It's easy to get bugs when doing that and hash bugs can definitely
mess up your threat detection.  I think I could help you out then :)

Michael

• Re: null move and mate threat Stuart Cracraft 16:42:48 10/08/04
  • Re: null move and mate threat Michael Henderson 17:37:29 10/08/04
    • Re: null move and mate threat Stuart Cracraft 07:00:05 10/09/04
      • Re: null move and mate threat Michael Henderson 10:39:01 10/09/04
      • Re: null move and mate threat Michael Henderson 10:25:14 10/09/04
  • Re: null move and mate threat Zach Wegner 17:03:43 10/08/04
    • Re: null move and mate threat Gerd Isenberg 06:58:38 10/09/04
      • Re: null move and mate threat Stuart Cracraft 07:02:13 10/09/04
        • Re: null move and mate threat Gerd Isenberg 10:05:32 10/09/04
          • Re: null move and mate threat Stuart Cracraft 14:32:05 10/09/04
    • Re: null move and mate threat Uri Blass 17:54:49 10/08/04
      • Re: null move and mate threat Stuart Cracraft 07:03:45 10/09/04
      • Re: null move and mate threat David B Weller 04:42:56 10/09/04
        • Re: null move and mate threat Brian Richardson 13:24:40 10/09/04
        • Re: null move and mate threat Stuart Cracraft 08:39:45 10/09/04
      • Re: null move and mate threat Zach Wegner 18:32:19 10/08/04
        • Re: null move and mate threat Stuart Cracraft 14:33:14 10/09/04
      • Re: null move and mate threat Dan Honeycutt 18:02:36 10/08/04
        • Re: null move and mate threat Stuart Cracraft 07:05:31 10/09/04
      • Re: null move and mate threat Uri Blass 17:56:20 10/08/04
    • Re: null move and mate threat Zach Wegner 17:05:29 10/08/04

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