Author: Christophe Theron
Date: 08:21:01 12/29/01
Go up one level in this thread
On December 27, 2001 at 19:35:26, Will Singleton wrote:
>On December 27, 2001 at 18:36:33, Uri Blass wrote:
>
>>On December 27, 2001 at 16:51:52, Rafael Andrist wrote:
>>
>>>On December 27, 2001 at 15:47:33, Uri Blass wrote:
>>>
>>>>7 plies to stop the qsearch is not a holy number and
>>>>I do not know the correct number but it is clear to me that
>>>>not stopping the qsearch at some point is illogical and there is a position when
>>>>Fritz needed an hour to find mate in 1 because of qsearch
>>>>explosion.
>>>
>>>A possible solution which is theoretically correct but a bit tricky to
>>>implement: stop qsearch after x plys and set an "incomplete" flag. If you
>>>recognize during search that the "incomplete" node can still change the value of
>>>the tree, do the qsearch again. (I don't do it yet.)
>>>
>>>> Limiting qsearch is, in my opinion, same as making
>>>>>it almost useless.
>>>>
>>>>
>>>>In most of the qsearches there are not lines of more
>>>>than 7 plies so I do not see why limiting the qsearch to
>>>>7 plies make it almost useless.
>>>
>>>if limiting the qsearch doesn't change much, why limit it and maybe lose
>>>critical information?
>>
>>
>>If in 100 cases it changes nothing and in 1 case I waste 100 more nodes because
>>of not limiting the qsearch then the 1 case may be important.
>>
>>If the price that you pay to get the information is too high and the information
>>is something that you relatively cannot trust then it may be better not to get
>>the information.
>>
>>If I continue to give ideas for free then I have no chance to have a top program
>>in the future so maybe it is better if I stop it.
>>
>>Uri
>
>I have always limited the qsearch (8 plies currently), but I think it is worth
>testing our suppositions occasionally. Changes in another part of the program
>can affect the efficacy of previously tested strategies. Like checks in
>qsearch, etc. So I will go ahead and remove the limit and run some tests. My
>feeling is that at 8 plies, little is gained or lost by assigning a limit.
>
>Uri, I'd say if you want to have a top program, you have to first follow in
>everyone else's footsteps. Then assess what is right and what is wrong, and
>what can be improved. As for me, I started by doing all my own ideas, and ended
>up years later by moving toward the norm. Not very efficient.
>
>Will
This is extremely efficient. You have learned what does not work by yourself.
You have narrowed the field of your future research at a stage when the program
was simple enough to experiment.
If you start by building a complete "classical" (Crafty clone) program and try
to experiment from it, you are going to spend a lot of time, because the program
is already too complex.
You did it the right way, in my opinion.
Actually that's what I have done myself, and I'm glad that I did!
Christophe
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