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Subject: Re: Behting position

Author: blass uri

Date: 03:16:01 09/01/98

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On September 01, 1998 at 05:28:48, Bernhard Bauer wrote:

>On August 30, 1998 at 09:46:29, Enrique Irazoqui wrote:
>
>>[Event ""Rigasche Rundschau""]
>>[Site "?"]
>>[Date "1907.??.??"]
>>[Round "?"]
>>[White "Behting"]
>>[Black "?"]
>>[Result "1-0"]
>>[SetUp "1"]
>>[FEN "8/8/8/5pp1/8/1K6/2pp1Q2/2k5 w - - 0 1"]
>>[PlyCount "5"]
>>[EventDate "1907.??.??"]
>>
>>1. Qe3 f4 2. Qf2 d1=Q (2... f3 3. Qe3) 3. Kc3 f3 4. Qe3+ Kb1 5. Qb6+ Kc1 6. Qb2#
>>1-0
>>
>>This is a relatively simple position where white wins in 12 plies or less, but
>>several programs fail to find Qe3, even after a search deeper than 12 plies.
>>
>>After at least 5 minutes on a PII-400 with 256 MB RAM, Hiarcs 6, Fritz 5, Mchess
>>7.1, Nimzo 98, Crafty 15.17, Exchess 2.34 and Junior 4.6 don’t find the
>>solution. Junior plays instantaneously Kc3?? and announces mate in 4,
>>overlooking the obvious underpromotion d1N+.
>>
>>Time to find Qe3 with a winning evaluation:
>>Genius 5W, 13 secs.
>>Rebel 9, 30 secs.
>>Rebel 10, 24 secs.
>>Shredder 2, 24 secs.
>>
>>Strange that there is so much difference between programs in this position.
>>
>>What would Ferret, Dark Thought and others play?
>>
>>Enrique
>
>Dear Enrique,
>
>Tu etiam ... !!!
>
>You should have known better -:) This type of positions *never* occurs in
>reall games and if it occurs than only in 0.0000000000001 % of all cases.

I am sure that it occurs more often but I understand the practical reasons for
not solving this position.

>Programmers are interested in playing games - not in solving studies!!
>By the way, a studie is a position we can not solve within a resonable amount
>of time. So not solving this position is a feature!
> And it makes the program
>faster and playing better in 99.9999999999999 % of all possible positions.

I do not agree about it because there is an option to use better rules when not
to use the null move feature.

Uri

>We have been told that so often that you should know.
>Or do you dare to say something against the null move feature?
>
>Here some output from a modified crafty - *no* null move.
>
>                                     Qe3+ Qd2 5. Qg1+ Qd1 6. Qe3+
>               11->  58.67  -0.66   1. Ka2 f4 2. Kb3 f3 3. Ka2 d1=Q 4.
>                                    Qe3+ Qd2 5. Qg1+ Qd1 6. Qe3+
>               12     1:43  -0.66   1. Ka2 d1=Q 2. Qe3+ Qd2 3. Qg1+ Qd1
>                                    4. Qe3+
>               12     2:49     ++   1. Qe3!!
>               12     3:06   5.96   1. Qe3 f4 2. Qf2 f3 3. Qe3 f2 4. Qxf2
>                                    g4 5. Qe3 g3 6. Kc3 Kb1 7. Kxd2
>               12->   3:06   5.96   1. Qe3 f4 2. Qf2 f3 3. Qe3 f2 4. Qxf2
>                                    g4 5. Qe3 g3 6. Kc3 Kb1 7. Kxd2
>               13     3:13     ++   1. Qe3!!
>               13     3:49   9.24   1. Qe3 f4 2. Qf2 f3 3. Qe3 g4 4. Kc3
>                                    Kb1 5. Qb6+ Kc1 6. Qb2+ Kd1 7. Qxc2+
>                                    Ke1 8. Qxd2+ Kf1 9. Qg5 Ke2 10. Qxg4
>               13->   5:41   9.24   1. Qe3 f4 2. Qf2 f3 3. Qe3 g4 4. Kc3
>                                    Kb1 5. Qb6+ Kc1 6. Qb2+ Kd1 7. Qxc2+
>                                    Ke1 8. Qxd2+ Kf1 9. Qg5 Ke2 10. Qxg4
>               14     6:00     ++   1. Qe3!!
>               14     8:03  Mat17   1. Qe3 f4 2. Qf2 f3 3. Qe3 g4 4. Kc3
>                                    Kb1 5. Qb6+ Kc1 6. Qb2+ Kd1 7. Qxc2+
>                                    Ke1 8. Qxd2+ Kf1 9. Qg5 Ke2 10. Qxg4
>
>               14->  13:02  Mat17   1. Qe3 f4 2. Qf2 f3 3. Qe3 g4 4. Kc3
>                                    Kb1 5. Qb6+ Kc1 6. Qb2+ Kd1 7. Qxc2+
>                                    Ke1 8. Qxd2+ Kf1 9. Qg5 Ke2 10. Qxg4
>
>              time: 13:02  cpu:200%  mat:6  n:158539669  nps:202622
>              ext-> checks:23356809 recaps:392669 pawns:1749198 1rep:4192114
>              predicted:0  nodes:158539669  evals:2801460
>              endgame tablebase-> probes done: 2012494  successful: 2012494
>              hashing-> trans/ref:70%  pawn:12%  used:w99% b99%
>
>mate in 17 moves.
>
>Please take the above with a grain of salt. -:)))
>Kind regards
>
>Bernhard



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