Author: Heiner Marxen
Date: 13:57:12 06/03/02
Go up one level in this thread
On June 02, 2002 at 17:28:13, Heiner Marxen wrote:
>On June 02, 2002 at 16:40:44, leonid wrote:
>
>>On June 02, 2002 at 15:54:40, Heiner Marxen wrote:
>>
>>>On June 02, 2002 at 08:20:52, leonid wrote:
>>>
>>>>On June 02, 2002 at 05:20:35, Tim Foden wrote:
>>>>
>>>>>On June 01, 2002 at 08:45:35, leonid wrote:
>>>>>
>>>>>>[D]Kn4QQ/RNQQQQQ1/nqrqqp2/qNRQq3/kBBp4/rbq5/Pb6/q7 w - -
>>>>>>
>>>>>>Please indicate your result.
>>>>>
>>>>>GLC 2.18, 24MB Hash, AXP 1.46GHz, finds that Bxb3+ is a mate in 10 after 21.04
>>>>>seconds.
>>>>>
>>>>>Cheers, Tim.
>>>>
>>>>Thanks, Tim!
>>>>
>>>>Since I see that you found mate at 10, I will try later at the same depth but
>>>>with much deeper selective. Before I used my usual, almost default selective
>>>>that make search at reasonable time. It is "mixed search" where initial brute
>>>>force search goes the most 3 moves deep (6 plys) before switching to "real
>>>>selective". I will try later to search 4 and 5 moves (8 and 10 plys) by brute
>>>>force before starting "real selective".
>>>>
>>>>Cheers,
>>>>Leonid.
>>>
>>>And according to Chest there is no mate in 9 (2 hours on K7/600, 350 MB hash).
>>>Since the EBF has increased up to above 18 in the last 2 depthes, it may
>>>take some time for Chest to complete depth 10. I'll follow-up, then.
>>>But so far it appears to be a mate-in-10 for sure.
>>
>>Thanks, Heiner!
>>
>>Now I know for sure that it is mate in 10. It could be useful for me to know
>>exact depth in the future. When I write something, I do use my old positions
>>(and many positions from books) for finding bugs. If one day my program will
>>find here mate in 9, then I will know that I must look into my code.
>>
>>My branching factor jumped so much on this position that 8 moves took already 1
>>hour to see it. I stopped right there. Branching between 7 and 8 moves was 24.
>>
>>Cheers,
>>Leonid.
>
>Mine was slightly better, so far:
>
># 3 0.01s 1kN [ 9.22] 0.93 74- 0
># 4 0.07s [ 7.00] 4kN [ 5.29] 1.02 509- 0
># 5 0.49s [ 7.00] 28kN [ 7.80] 1.14 3169- 0
># 6 2.88s [ 5.88] 168kN [ 6.05] 1.39 13961- 0
># 7 25.72s [ 8.93] 1616kN [ 9.63] 1.64 120110- 0
># 8 412.67s [ 16.04] 28303kN [ 17.51] 1.92 1825814- 32
># 9 7533.33s [ 18.26] 524949kN [ 18.55] 2.03 33174075- 24426174
>
>But it may jump once more for depth 10, we'll have to wait and see.
After 22 hours Chest says "mate in 10" with 4 key moves:
# 10 78888.71s [ 10.47] 5395652kN [ 10.28] 2.45 340008494- 331260593
Bc4 : b3
Bb4 : a5
Qc7 : b6
Qc7 : d6
5 hours later he tells the PVs:
PV: Bxb3+ Qxb3 axb3+ Rxb3 Nc3+ Rxc3 Rxa5+ Kxb4 Qxb6+ Rxb6 Rb5+ Ka3 Qexd6+ Q5xd6
Ra5+ Kb4 Q7b5+ Rxb5 Qxb5#
PV: Bxa5 Nxc7+ Qxc7 Na6 Nxc3+ Bxc3 Qxb6 Rc8+ Qxc8 Qxc8+ Rxc8 Qb8+ Rxb8 Nc7+
Qbxc7 Qxd5 Bb4+ Qa5 Nc5#
PV: Qxb6 Qxb6 Rxc6 Nxc6 Qd7xe6 Qdd8+ Qdxd8 Qb8+ Qxb8 Bxc4 Nc5+ Qxc5 Rxa6+ Na5
Rxa5+ Kxb4 Qxc5+ Kxc5 Qg8f8#
PV: Qcxd6 Bxc4 Nxc3+ Bxc3 Rxa5+ Qxa5 Q7xc6+ Nxc6 Q5xc6+ Bb5 Bxa5 Qc8+ Qcxc8 Nc7+
Bxc7+ Ba6 Rxa6+ Qa5 Qge8#
(which are taken from the hash table, and must be recomputed, if not there,
any more)
Cheers,
Heiner
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