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Subject: Re: null move and mate threat

Author: Uri Blass

Date: 12:19:37 10/09/04

Go up one level in this thread


On October 09, 2004 at 11:37:59, Stuart Cracraft wrote:

>On October 08, 2004 at 23:02:52, Uri Blass wrote:
>
>>On October 08, 2004 at 22:02:41, Andrew Platt wrote:
>>
>>>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???
>>>
>>>When I added it I had to systematically go through my code and find all the
>>>places I returned alpha & beta and change them to return the actual score. This
>>>included the hash table code.
>>>
>>>Andy.
>>
>>I did not need to do it
>>returning mate or -mate when the score is mate in the qsearch was enough for me.
>>
>>The new version is better in the ecm-gcp test suite  but I need to test to see
>>if it is better in games.
>>
>>Uri
>
>Uri -- please post movei's wac 141 search.
>
>Stuart

Here is analysis of latest version that needs 115413 nodes and 0.23 seconds on
A3000 to find it.

I believe that I am going to improve it in a productive way for games.

7469 >first : analyze
7547 <first :  1 -214 0 195 g2f1 e8e2
7547 <first :  2 -214 0 246 g2f1 e8e2
7547 <first :  2 -214 0 280 g2f1 e8e2
7562 <first : 3 -184 0 732 g2f1
7562 <first :  3 -167 0 1157 g2f1 f4d3 c1h6
7562 <first :  3 -167 0 1263 g2f1 f4d3 c1h6
7562 <first :  4 -189 1 3802 g2f1 e8e2 h1h2 g8h7
7562 <first :  4 -189 1 4549 g2f1 e8e2 h1h2 g8h7
7578 <first :  5 -174 3 10104 g2f1 a7a5 h1g1 a5a4 b3d1
7578 <first :  5 -174 3 11204 g2f1 a7a5 h1g1 a5a4 b3d1
7641 <first :  6 -147 9 40244 g2f1 g8h7 f6g5 f4e2 c1c2 f7f5
7641 <first :  6 -147 9 41902 g2f1 g8h7 f6g5 f4e2 c1c2 f7f5
7766 <first :  7 -147 20 102434 g2f1 g8h7 f6g5 f4e2 c1c2 f7f5 h1h3
7781 <first : 7 -146 23 115413 c1f4
7797 <first : 7 -117 25 121900 c1f4
7906 <first :  7 308 35 176627 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7h2 h6h2
7906 <first :  7 308 35 176905 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7h2 h6h2
7906 <first : 8 278 35 177935 c1f4
8031 <first :  8 338 48 241747 c1f4
8047 <first :  8 338 50 245983 c1f4
8281 <first : 9 368 73 370747 c1f4
8719 <first : 9 438 117 601258 c1f4
12484 <first :  9 983 493 2496556 c1f4 d6e7 h4h5 e7f6 f4f6 g6h5 f6g5 g8f8 h1h5
c7g3 g2g3
12484 <first :  9 983 493 2498911 c1f4 d6e7 h4h5 e7f6 f4f6 g6h5 f6g5 g8f8 h1h5
c7g3 g2g3
14453 <first : 10 1013 690 3473214 c1f4
16766 <first : 10 1083 921 4639706 c1f4
27984 <first :  10 1654 2042 10083048 c1f4 d6e7 h4h5 e7f6 f4f6 c7g3 f2g3 e8e2
g2f1 g6h5 f1e2 b5b4 h1h5
28031 <first :  10 1654 2048 10116184 c1f4 d6e7 h4h5 e7f6 f4f6 c7g3 f2g3 e8e2
g2f1 g6h5 f1e2 b5b4 h1h5
35719 <first : 11 1684 2817 14025575 c1f4
43516 <first : 11 1754 3595 17869553 c1f4
65328 <first :  11 1885 5778 28738929 c1f4 d6e5 d4e5 c7e5 f6e5 d7d5 b3d5 c6d5
h1d1 e8d8 e5d4
65500 <first :  11 1885 5795 28845104 c1f4 d6e5 d4e5 c7e5 f6e5 d7d5 b3d5 c6d5
h1d1 e8d8 e5d4
75484 <first : 12 1915 6793 33733458 c1f4
86656 <first : 12 1985 7909 38974215 c1f4
200453 <first :  12 9989 19289 95651665 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3
g2g3 e8f8 h6h8
200484 <first :  12 9989 19293 95684529 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3
g2g3 e8f8 h6h8

Uri



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