Author: leonid
Date: 15:05:23 04/06/02
Go up one level in this thread
On April 06, 2002 at 16:48:36, Heiner Marxen wrote:
>On April 06, 2002 at 15:53:05, leonid wrote:
>
>>On April 06, 2002 at 14:32:56, John Merlino wrote:
>>
>>>On April 06, 2002 at 07:05:42, leonid wrote:
>>>
>>>>[D]8/8/q4Q2/rBpnqQ2/QNnNbN2/NqrPnQ2/NbrkqB2/QKRqRq2 w - -
>>>>
>>>>Please indicate your result.
>>>>
>>>>Thanks,
>>>>Leonid.
>>>
>>>Chessmaster says Mate in 11 after 48 seconds on a PIII-733. But is that the
>>>shortest mate?
>>
>>I really don't know. I went only 9 moves by brute force and stop there. My
>>program don't use hash and its absence make search slow on similar position.
>>
>>Maybe somebody will run this position on Chest with hash 10 moves deep. This
>>program use hash and have usually good branching factor to do brute force work.
>>
>>My selective (LLchess mate solver) found mate in 11 moves, just like
>>Chessmaster. On Celeron 600Mhz it found mate in 9 seconds.
>>
>>Cheers,
>>Leonid.
>>
>>>
>>>Time Depth Score Positions Moves
>>>0:07 1/3 6.58 440512 1.Nxb3+ Rxb3 2.Qxe2+ Qfxe2 3.Rxe2+
>>> Qxe2 4.Rxc2+ Kd1 5.Rc1+ Bxc1+ 6.Qxb3+
>>> Nc2 7.Nxc4 Qxa1+ 8.Qxa1 Bxf5 9.Nxe2
>>> Rxb5
>>>0:34 1/4 9.82 2017709 1.Nxb3+ Rxb3 2.Qxe2+ Qfxe2 3.Rxe2+
>>> Qxe2 4.Rxc2+ Kd1 5.Rc1+ Bxc1+ 6.Qxb3+
>>> Nc2 7.Nxc4 Qexf6 8.Qfxf6 Rxa2 9.Nxc2
>>>0:48 1/4 Mate11 2932963 1.Nxc4+ Qxc4 2.Bxe3+ Nxe3 3.Qxe3+
>>> Kxe3 4.Nfd5+ Qexd5 5.Ndxc2+ Rxc2
>>> 6.Nxd5+ Kd2 7.Rxe2+ Qfxe2 8.Qf4+
>>> Ke1 9.Q6h4+ Qf2 10.Qhxf2+ Rxf2
>>> 11.Qxd1#
>>>1:34 2/5 Mate11 6346069 1.Nxc4+ Qxc4 2.Bxe3+ Nxe3 3.Qxe3+
>>> Kxe3 4.Nfd5+ Qexd5 5.Ndxc2+ Rxc2
>>> 6.Nxd5+ Kd2 7.Rxe2+ Qfxe2 8.Qf4+
>>> Ke1 9.Q6h4+ Qf2 10.Qhxf2+ Rxf2
>>> 11.Qxd1#
>>>
>>>jm
>
>Chest confirms that this is the shortest solution. 54.3 minutes on my old
>K7/600 with 350 MB hash:
>
>PV: Nxc4+ Qxc4 Bxe3+ Nxe3 Qxe3+ Kxe3 Nfd5+ Qexd5 Ndxc2+ Qxc2+ Nxc2+ Rxc2 Rxe2+
>Qxe2 Qf4+ Kxd3 Qb3+ Rc3 Rd1+ Qxd1+ Qxd1#
>
>The hash table appears to help a lot with this position.
>
># 4 0.10s [ 5.00] 6kN [ 6.52] 1.16 559- 0
># 5 0.43s [ 4.30] 26kN [ 4.40] 1.44 2452- 0
># 6 1.53s [ 3.56] 91kN [ 3.51] 2.11 9102- 0
># 7 5.65s [ 3.69] 342kN [ 3.78] 4.92 31794- 0
># 8 28.54s [ 5.05] 1796kN [ 5.25] 6.44 145284- 0
># 9 185.90s [ 6.51] 12445kN [ 6.93] 7.17 765247- 0
># 10 1043.77s [ 5.61] 70684kN [ 5.68] 10.44 4164086- 8572
># 11 3260.28s [ 3.12] 217250kN [ 3.07] 14.33 13498171- 4802820
> ^^^^^ hash table factor
Thanks, Heiner!
Mine took already 54 minutes to see 9 moves. In my search branching jumped
dramatically between 8 and 9 move.
Celeron 600Mhz. No hash:
Moves Time Branching factor NPS
4 0.38 sec 261k
4.42
5 1.7 sec 181k
4.48
6 7.63 sec 107k
4.77
7 36 sec 149k
6.63
8 4 min 2 sec 317k
13.3
9 53 min 40 sec 325k
Cheers,
Leonid.
>Cheers,
>Heiner
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