Author: Heiner Marxen
Date: 13:48:36 04/06/02
Go up one level in this thread
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
Cheers,
Heiner
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