Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Mate in 46

Author: Heiner Marxen

Date: 04:47:52 02/02/01

Go up one level in this thread


On February 01, 2001 at 17:47:23, Ignacio Santos Crespo wrote:

>On January 31, 2001 at 11:25:25, Enrique Irazoqui wrote:
>
>>On January 31, 2001 at 10:25:50, Heiner Marxen wrote:
>>
>>>On January 30, 2001 at 17:15:45, Olaf Jenkner wrote:
>>>
>>>>Perhaps I had in mind this problem what is easily to prove that there is
>>>>no shorter mate.
>>>>
>>>>Pervakow/Sum.  #46
>>>>[D]2N5/p4P2/p4RqP/P2krb2/5RNK/2PPBnP1/3P1pP1/5Q2 w - - 1 0
>>>
>>>Yes, that can be.  Much to my own surprise Chest really proves this
>>>as a mate in 46 moves, and needs just 8.2 seconds (K7/600) for it.
>>>It gives the following PV:
>>>
>>> 1. gxf3  Qh5+
>>> 2. Kxh5  Bg6+
>>> 3. Kxg6  Rg5+
>>> 4. Kh7   Rg7+
>>> 5. Kh8   Rh7+
>>> 6. Kg8   Rh8+
>>> 7. Kg7   Rh7+
>>> 8. Kf8   Rh8+
>>> 9. Ke7   Re8+
>>>10. Kd7   Rd8+
>>>11. Kc7   Rd7+
>>>12. Kb8   Rb7+
>>>13. Ka8   Rb8+
>>>14. Kxa7  Rb7+
>>>15. Kxa6  Ra7+
>>>16. Kb5   Rxa5+
>>>17. Kb4   Rb5+
>>>18. Ka3   Rb3+
>>>19. Ka2   Rb2+
>>>20. Ka1   Ra2+
>>>21. Kb1   Rb2+
>>>22. Kc1   Rb1+
>>>23. Kc2   Rb2+
>>>24. Kd1   Rb1+
>>>25. Ke2   Re1+
>>>26. Kxf2  Re2+
>>>27. Kg1   Rg2+
>>>28. Kh1   Rg1+
>>>29. Kh2   Rh1+
>>>30. Kg2   Rg1+
>>>31. Kh3   Rxg3+
>>>32. Kh4   Rh3+
>>>33. Kg5   Rh5+
>>>34. Kg6   Rg5+
>>>35. Kh7   Rg7+
>>>36. Kh8   Rh7+
>>>37. Kg8   Rh8+
>>>38. Kg7   Rh7+
>>>39. Kg6   Rg7+
>>>40. Kh5   Rg5+
>>>41. Kh4   Rh5+
>>>42. Kg3   Rh3+
>>>43. Kf2   Rxf3+
>>>44. Ke2   Rf2+
>>>45. Nxf2  Ke5
>>>46. R4f5#
>>>
>>>I even had to increase the maximal allowed depth in Chest (formerly 30).
>>>Quite an exceptional position!
>>>
>>>Can the playing programs solve this, also?  I suspect so.
>>
>>92 plies? You must be kidding. They pick gxf3 instantly with a huge score, but
>>no mate. I only tried Deep Fritz, Gambit Tiger and Shredder 5, but I don't think
>>any playing program will see it.
>>
>>Enrique
>>
>>>Heiner
>
>On my Pentium 166 after 2... Bg6+, Junior 6 (with 15 Mb. hash) say mate in 42
>(62")

While I'm pleased to hear that a program solved this one,  from the above
I believe "mate in 44" would be correct, not "mate in 42".  Can you show
us a PV?  I would like to check it.  Someone errs, and I'd like to know who.

Heiner



This page took 0.01 seconds to execute

Last modified: Thu, 07 Jul 11 08:48:38 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.