Author: Heiner Marxen
Date: 04:13:28 02/13/01
Go up one level in this thread
On February 13, 2001 at 01:32:05, Jeremiah Penery wrote:
>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
This is the line of Chest (there may be others):
1...Qaxf7 Bxg7+ Nfxg7 Qgxg6 Ndf5 Nxf7+ Qxf7 Qgxf5 Ngf6 Qxh7+ Nxh7 Qxh7#
Ne4 Nxf7+ Qxf7 Qg6xe4 Ngf6 Qxh7+ Nxh7 Qxh7#
Q6xg6 Nxf7+ Nxf7 Qgxg6 Ng5 Qxh7+ Nxh7 Qxh7#
hxg6 Qgxg6 Ndf5 Rxh5+ Ngh6 Rxh6+ =*= Qh7#
Ngf5 Nxf7+ Nxf7 Qxg8+ Rxg8 Qgxg8#
Q7xg6 Qxg8+ Kxg8 Qxf8+ Qxf8 Qfxf8#
Qf5 Nxf7+ Nxf7 Qgxg7+ Nxg7 Qgxg7#
Heiner
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