Author: Jeremiah Penery
Date: 22:32:05 02/12/01
Go up one level in this thread
On February 12, 2001 at 18:40:38, Heiner Marxen wrote:
>On February 12, 2001 at 15:47:55, leonid wrote:
>
>>On February 12, 2001 at 13:11:53, Heiner Marxen wrote:
>>
>>>On February 12, 2001 at 07:29:02, leonid wrote:
>>>
>>>>Hi!
>>>>
>>>>If you like to solve a mate, try this position:
>>>>
>>>>[D]rQ1Q1rnk/q4qbp/3nQqbB/q1Q1NnNn/5QQ1/b2Q4/1QB3Q1/1K1R3R w - -
>>>>
>>>>Please, indicate your result.
>>>>
>>>>In dispite that this position is not that deep and difficult, if your program
>>>>don't know how to deel with white crowd it could be in serious trouble. My was
>>>>deadly slow in searching for mate even by selective search. Reason - white have
>>>>142 initial moves and goes beyond 150 during the search for mate. Good challenge
>>>>for every chess program!
>>>>
>>>>Thanks for responding,
>>>>Leonid.
>>>
>>>Hmmm, not deep? Not difficult? "There is no mate in 6" by Chest burns
>>>nearly 18 minutes on a K6-3/400 with 50MB hash. I have started depth=7,
>>>but I expect at least 3 hours to complete it, and may be more.
>>>At least I can confirm the 142 initial legal moves.
>>>
>>>Heiner
>>
>>Thanks, Heiner! You are very close! Mine found mate in 8 by selective. It was
>>long. Took 1 min 17 sec.
>>
>>It is simple since there are not that many moves before the mate and starting
>>move (for 8 moves) is checking one.
>>
>>Leonid.
>
>Phew, that was hard work: after 5.3 hours (K6-3/400, 50MB hash) Chest finds
>a unique key for a mate in 7. Here is a PV:
>
>Ngxf7+ Nxf7 Nxg6+ hxg6 Bxg7+ Nfxg7 Qgxh5+ Nxh5 Qfxf6+ Ngxf6 Qdxf8+ Kh7 Qgxg6#
How does the solution go after Ngxf7+ Qaxf7 ? I guess I ask because my Crafty
(with SE enabled) acts strangely here:
5 3:11 Mat07 1. Ngxf7+ Nxf7 2. Nxg6+ Qxg6 3. Bxg7+
Nhxg7 4. Qgxg6 N7h6 5. Qxh7+ Kxh7 6.
Qfxh6+ Nxh6 7. Rxh6# <HT>
5-> 3:12 Mat07 1. Ngxf7+ Nxf7 2. Nxg6+ Qxg6 3. Bxg7+
Nhxg7 4. Qgxg6 N7h6 5. Qxh7+ Kxh7 6.
Qfxh6+ Nxh6 7. Rxh6# <HT>
6 4:33 -- 1. Ngxf7+
6 6:48 Mat09 1. Ngxf7+ Qaxf7 2. Bxg7+ Nfxg7 3. Nxf7+
Nxf7 4. Qgxg6 hxg6 5. Qexf6 Bxb2 6.
Rxh5+ Nfh6 7. Rxh6+ Nxh6 8. Qxh6+ Kg8
9. Qdxf8# <HT>
6-> 6:54 Mat09 1. Ngxf7+ Qaxf7 2. Bxg7+ Nfxg7 3. Nxf7+
Nxf7 4. Qgxg6 hxg6 5. Qexf6 Bxb2 6.
Rxh5+ Nfh6 7. Rxh6+ Nxh6 8. Qxh6+ Kg8
9. Qdxf8# <HT>
7 11:07 Mat08 1. Ngxf7+ Qaxf7 2. Bxg7+ Nfxg7 3. Nxf7+
Nxf7 4. Qdxg6 hxg6 5. Qfxf6 Bxb2 6.
Qgxh5+ Nfh6 7. Qxh6+ Nxh6 8. Rxh6#
<HT>
7-> 13:04 Mat08 1. Ngxf7+ Qaxf7 2. Bxg7+ Nfxg7 3. Nxf7+
Nxf7 4. Qdxg6 hxg6 5. Qfxf6 Bxb2 6.
Qgxh5+ Nfh6 7. Qxh6+ Nxh6 8. Rxh6#
<HT>
I tried searching after Ngxf7+ Qaxf7 and the shortest mate it could find was
Mate in 7.
Jeremiah
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