Author: Dann Corbit
Date: 14:29:19 01/26/04
Go up one level in this thread
On January 26, 2004 at 17:14:34, Dann Corbit wrote:
>On January 26, 2004 at 17:00:45, Will Singleton wrote:
>
>>On January 26, 2004 at 16:56:12, Dann Corbit wrote:
>>
>>>On January 26, 2004 at 16:50:51, Will Singleton wrote:
>>>
>>>>On January 26, 2004 at 16:15:51, Dann Corbit wrote:
>>>>
>>>>>There have been some recent changes to Olithink (mostly suggestions from Michel
>>>>>Langeveld due to his work on TSCPGothic).
>>>>>
>>>>>Due to these changes, Olithink is playing surprisingly well.
>>>>>
>>>>>Is there someone with a fast machine who would be available to operate Olithink?
>>>>>
>>>>>Dr. Brausch will be avaialable sometimes to kibits along with the games, but he
>>>>>would not be able to attend all of the games.
>>>>
>>>>I believe the deadline for entry has passed. However, I would support holding a
>>>>program in reserve (like Olithink) in case of an odd # of entries.
>>>
>>>Too bad about the deadline.
>>>
>>>I saw this post this morning:
>>>"CCT6: Now 53 Participants - Hiarcs join - DEADLINE Today 8,5h left"
>>>
>>>And I did not look carefully at the date/time of the post.
>>>
>>>The latest iteration of Olithink would have been very competitive, I think.
>>>
>>>A few simple changes made a gigantic leap of strenght.
>>
>>It would certainly be informative to look at the changes.
>
>They were already discussed here for the most part. Michel Langeveld noticed
>the following:
>
>1. Deep searches were ignored (e.g. the check was for h->depth == depth rather
>than h->depth >= depth).
>2. All exact hash results were ignored (only high and low bounds were used)
>3. I added a simple IID like this (the Beowulf IID):
>
> /* ----------==== INTERNAL ITERATIVE DEEPENING ====----------- */
>
> /* If we're not doing a NULL move and we don't have a hash move and we're
> * at least 3 ply away from the quiescence search, then try to get a good
> * guess for the best move by doing a shallower search from here. */
> if (depth >= 3 && !do_null) {
> w = search(on_move, ply, depth-2, alpha, beta, do_null, 1);
> /* Re-search properly if the previous search failed low, so that we
> * know we're getting a good move, not just the move with the highest
> * upper bound (which is essentially random and depends on the search
> * order.) */
> if (w <= alpha)
> w = search(on_move, ply, depth-2, -32500, alpha+1, do_null, 1);
> }
>
>
>> Are they available
>>somewhere?
>
>I can mail you a copy, but he is making a few fixes right now. I broke the
>resign feature, so that it sometimes resigns inappropriately.
>
>>(did you receive my note re the other exe?)
>
>Yes. I will take a look.
The binary is here:
ftp://cap.connx.com/chess-engines/new-approach/olithink412.exe
The source code is here:
ftp://cap.connx.com/chess-engines/new-approach/olithink412.c
The source code I put there has problems (it sometimes makes bad resignation
results).
But it should be fine to test against EPD sets using Bruce Moreland's tool.
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