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Subject: Re: Mystery solved by Gambit Tiger

Author: Hermano Ecuadoriano

Date: 12:42:22 02/02/01

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On February 02, 2001 at 14:37:29, David Dahlem wrote:

>
>On February 02, 2001 at 10:16:34, Hermano Ecuadoriano wrote:
>
>>On February 02, 2001 at 08:14:03, David Dahlem wrote:
>>
>>>
>>>On February 02, 2001 at 07:53:30, Hermano Ecuadoriano wrote:
>>>
>>>>On February 02, 2001 at 03:19:14, Timothy J. Frohlick wrote:
>>>>
>>>>>On February 02, 2001 at 01:28:59, Jouni Uski wrote:
>>>>>
>>>>>>[D]8/6kn/3B3p/5K1B/8/8/8/8 b - -
>>>>>>
>>>>>>resign 1-0! Why? Is this really white's win?
>>>>>>
>>>>>>JouniDate: 1/2/2001
>>>>>
>>>>>Jouni,
>>>>>
>>>>>Gambit Tiger without tablebases solves this as a mate in 46 in 26 minutes on a
>>>>>PII 333 with 48 Megs Hash.
>>>>>
>>>>>1... Ng5 2. Bc5 Nf7 3. Bd4+ Kf8 4. Kf6 Ng5 5. Bc5+ Kg8 6. Kf5 Nf7 7. Be7 Ng5 8.
>>>>>Bb4 Nf7 9. Kg6 Ne5+ 10. Kf6 Nd7+ 11. Ke7 Ne5 12. Bc3 Nc6+ 13. Ke8 Kh7 14. Kf7
>>>>>Ne5+ 15. Kf6 Nc6 16. Bf3 Nd8 17. Bb4 h5 18. Be4+ Kh8 19. Be7 Nc6 20. Bxc6 Kh7
>>>>>21. Be4+ Kg8 22. Kg6 Kh8 23. Bd5 h4 24. Bf6#
>>>>
>>>>I can't come anywhere close to duplicating this. In fact, I can play forward all
>>>>the way to the position after 15. Kf6, and it still takes 6 minutes to
>>>>find a mate. And then, it isn't nine more moves, as your solution suggests.
>>>>It says mate in 16. That would be a total of 61 plies from the initial position.
>>>>That's a bit of a stretch, even for Gambit Tiger.
>>>>Maybe I've done something wrong. I hope someone else will try this.
>>>>
>>>I'm not really sure if 2.Nf7 is black's best choice. I did some infinite
>>>analysis with Fritz 6 and Nimzo 8. They both like 2....Nh3 and stayed there for
>>>at least 10 minutes.
>>
>>This isn't about just GOOD moves: I think Timothy J. Frohlick posted that
>>Gambit Tiger found a FORCED MATE in 24 as given above, without TBs of
>>course. My Gambit Tiger comes NOWHERE CLOSE, and I am very curious whether
>>or not one of us has made a mistake. (I have other reasons for thinking that
>>I might be doing something wrong, and I'm on the lookout.)
>>
>>>
>>>Dave
>
>Maybe i'm just dumb but how can there be a FORCED mate if black has better
>alternative moves??
>
>Dave

The question was about some analysis that appeared to show a proven mate in
24 moves. To challenge that with a different program, it is not enough to show
that it likes a different move for some minutes. You would have to show that
Fritz had proven that its move avoids mate for AT LEAST 24+ moves. Then we
would know that the first analysis was wrong. I didn't think you were claiming
that. (Were you?) Thus, I thought that Fritz's opinion was irrelevant to the
issue at hand.

There is an important misunderstanding about these mate announcements from
the TB equipped programs.



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