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Subject: Re: If you want solve one mate...

Author: leonid

Date: 13:50:39 01/22/01

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On January 22, 2001 at 14:02:25, Gian-Carlo Pascutto wrote:

>On January 22, 2001 at 12:15:02, leonid wrote:
>
>>Program is Sjeng 8.5?
>
>Yes
>
>>Is this Cyrix CPU 120 Mhz?
>
>Yes
>
>>500000 nodes is the total number of nodes seen before finding the result?
>
>No. That is the maximum size the search tree can be. Sjeng's matefinder
>stores _all_ nodes into memory. You can make the tree as large as your
>available memory. 500000 nodes equals about 16M of RAM, which was the
>limit I had set for this try.
>
>The actual number of nodes searched was 404050.
>
>>>P: 0 D: 100000000 N: 404050 S: 404049 Mem: 10.79M Iters: 4151
>>>Time : 172.480000
>>
>>172 seconds?
>
>Yes.
>
>>
>>>This position is WON.
>>
>>In how many moves?
>
>No way to tell for sure. The algorithm is highly selective best-first
>so there is no guarantee whatsoever that what it finds is the shortest
>mate. You could establish a lowerbound by checking the maximum depth it
>reached, but it follows forced lines very deeply...

Thanks for responding! It was very interesting to read.

I am afraid that my last question was not correctly understood. Maybe my way of
saking was not clear. It is possible. I wanted to know how many moves deep
program looked before finding this mate. I had the impression that your program
just goes automatically searching for the mate, never mind how deep it is. I am
wrong?

Leonid.

>GCP



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