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Subject: Re: Strange, Hiarcs 7.32 announces mate in 43 after key move 1.Ne1

Author: Jeremiah Penery

Date: 00:41:41 04/02/00

Go up one level in this thread


On April 01, 2000 at 09:28:59, Laurence Chen wrote:

>On March 31, 2000 at 02:29:31, Jeremiah Penery wrote:
>
>>This position came from Valentin Albillo's site, on one of the endgame pages.
>>
>>In this position:
>>
>>[D]8/8/8/8/3p4/2k1p3/2N1P3/3K4 w - -
>>
>>White is supposed to capture the first black pawn on ply 39 (move 20), and the
>>second one shortly after.  I ran my modified Crafty on this with all 5-man TBs
>>to a depth of 45, with some strange results:
>>
>>White(1): 8/8/8/8/3p4/2k1p3/2N1P3/3K4/ w
>>analyze.White(1): end-game phase
>>              clearing hash tables
>>              time surplus   0.00  time limit 30.00 (3:00)
>>         nss  depth   time  score   variation (1)
>><It's not very interesting until about here.>
>>               37->  58:30   0.78   1. Ne1 Kb3 2. Nd3 Kc3 3. Ne5 Kb3 4.
>>                                    Nd3
>>               38    58:37     --   1. Ne1
>>               38    58:41     ++   1. Ne1!!
>>               38    62:52   4.54   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc1 Kb2 4.
>>                                    Na2 Kb1 5. Nb4 Kb2 6. Nd5 Kb3 7. Nc7
>>                                    Kc3 8. Nb5+ Kc4 9. Nd6+ Kb3 10. Ne4
>>                                    Kb2 11. Nc5 Kc3 12. Ke1 Kb2 13. Ne6
>>                                    Kc3 14. Nf4 Kc4 15. Kf1 Kc5 16. Kg2
>>                                    Kd6 17. Nd3 Ke7 18. Kf3 Kf8 19. Ke4
>>                                    Kg7 20. Kxd4 Kf6 21. Kxe3
>>
>><This is what the analysis shows should happen, approximately.  Looks good so
>>far.  We're into TBs now, but since it's too close to the leaf, Crafty doesn't
>>probe them here, I think.>
>>
>>               38->  62:52   4.54   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc1 Kb2 4.
>>                                    Na2 Kb1 5. Nb4 Kb2 6. Nd5 Kb3 7. Nc7
>>                                    Kc3 8. Nb5+ Kc4 9. Nd6+ Kb3 10. Ne4
>>                                    Kb2 11. Nc5 Kc3 12. Ke1 Kb2 13. Ne6
>>                                    Kc3 14. Nf4 Kc4 15. Kf1 Kc5 16. Kg2
>>                                    Kd6 17. Nd3 Ke7 18. Kf3 Kf8 19. Ke4
>>                                    Kg7 20. Kxd4 Kf6 21. Kxe3
>>               39    63:01     ++   1. Ne1!!
>>               39-> 124:20   4.93   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc1 Kb2 4.
>>                                    Na2 Kb1 5. Nb4 Kb2 6. Nd5 Kb3 7. Nc7
>>                                    Kc3 8. Nb5+ Kc4 9. Nd6+ Kb3 10. Ne4
>>                                    Kb2 11. Nc5 Kc3 12. Ke1 Kb2 13. Ne6
>>                                    Kc3 14. Nf4 Kc4 15. Kf1 Kc5 16. Kg2
>>                                    Kd6 17. Nd3 Ke7 18. Kf3 Kf8 19. Ke4
>>                                    Kg7 20. Kxd4 Kf6 21. Kxe3
>>               40   125:13     ++   1. Ne1!!
>>               40-> 417:29   5.32   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc1 Kb2 4.
>>                                    Na2 Kb1 5. Nb4 Kb2 6. Nd5 Kb3 7. Nc7
>>                                    Kc3 8. Nb5+ Kc4 9. Nd6+ Kb3 10. Ne4
>>                                    Kb2 11. Nc5 Kc3 12. Ke1 Kb2 13. Ne6
>>                                    Kc3 14. Nf4 Kc4 15. Kf1 Kc5 16. Kg2
>>                                    Kd6 17. Nd3 Ke7 18. Kf3 Kf8 19. Ke4
>>                                    Kg7 20. Kxd4 Kf6 21. Kxe3
>>
>><Still, looking good, as before.>
>>
>>               41   418:44     --   1. Ne1
>>               41   421:21   0.00   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc5 Kc4 4.
>>                                    Ne4 d3 5. exd3+ <HT>
>>
>><What happened?  The drawscore remains until...>
>>
>>               43-> 530:24   0.00   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc5 Kc4 4.
>>                                    Ne4 d3 5. exd3+ <HT>
>>               44   548:34     ++   1. Ne1!!
>>               44-> 1233:04   0.39   1. Ne1 Kb2 2. Nd3+ Kc3 3. Nc5 Kc4 4.
>>                                    Ne4 d3 5. exd3+ <HT>
>>               45   1234:35     ++   1. Ne1!!
>>
>><Will the score go back up again?  Will it find mate from the TBs?>
>>
>>I'm wondering if someone with a faster machine, with more memory (for TB cache,
>>primarily - my HD was going nuts, practically grinding my whole machine to a
>>halt) could run this until it sees mate.  I'd like to know how far out it is. :)
>>
>>Thanks,
>>Jeremiah
>I tried with Hiarcs 7.32 in my Pentium III 500MHz, 128 MB Hashtable, with all 5
>men tablebases.  After playing the first key move 1. Ne1 it announces mate in
>43.  However, when I play the next move for Black, it does not see mate !!!
>Would anyone know why?
>Laurence

How long does it take to declare the mate in 43?  That's pretty impressive,
since it's 40 ply before the position becomes a TB position, and I'm not sure
how close Hiarcs probes the TBs from the leaf nodes...



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