Author: Christophe Theron
Date: 19:10:45 02/07/04
Go up one level in this thread
On February 07, 2004 at 18:44:14, Torstein Hall wrote:
>On February 06, 2004 at 20:04:48, Christophe Theron wrote:
>
>>On February 06, 2004 at 19:33:22, Bob Durrett wrote:
>>
>>>On February 06, 2004 at 19:18:54, Christophe Theron wrote:
>>>
>>>>On February 06, 2004 at 13:48:48, Jaime Benito de Valle Ruiz wrote:
>>>>
>>>>>This endgame study can be game following the sequence
>>>>>
>>>>>1.Bd1 g1Q 2.Bxa4 Qc1 3.Bxd7 h5 4.Be8 h4 5.Ba4 Line
>>>>>
>>>>>[d] 8/3p4/p6p/k2N3B/p7/K6p/PP4pP/8 w - - 0 1
>>>>>
>>>>>Many engines (Fritz 8, Hiarcs 8, Ruffian 1.01) cannot win this endgame, probably
>>>>>due to the well known null-move problem for extreme and rare positions such as
>>>>>this.
>>>>>
>>>>>They just don't find 5. Ba4
>>>>>
>>>>>Try your engine after 4...,h4
>>>>>
>>>>>[d]8/3p4/p6p/k2N3B/p7/K6p/PP4pP/8 w - - 0 1
>>>>>
>>>>>All the above mentioned engines play 5.Bd7 and get a draw instead of winning.
>>>>>
>>>>>Regards,
>>>>>
>>>>> Jaime
>>>>
>>>>
>>>>
>>>>Chess Tiger X: 1.15 second on PIII-M 933MHz (Dell X200), 6Mb HT:
>>>>
>>>>N14 0.33s Bd1 g1=Q Bxa4 Qc1 Bxd7 h5 Be8 h4 Bd7 Qxb2+ Kxb2 0.00
>>>>N15 0.66s Bd1 g1=Q Bxa4 Qc1 Bxd7 h5 Be8 h4 Bd7 Qxb2+ Kxb2 +0.90
>>>>N15 1.15s Bd1 g1=Q Bxa4 Qc1 Bxd7 h5 Be8 h4 Ba4 Qxb2+ Kxb2 Kxa4 Kc... +3.26
>>>>
>>>>
>>>>
>>>> Christophe
>>>
>>>The key question to be answered is:
>>>
>>>"What is there about Chess Tiger X that is different from the other engines
>>>mentioned which accounts for the fact that they could not find the move but
>>>TigerX could? Is the "null-move problem" not applicable to TigerX or is there
>>>some other reason?
>>>
>>>Bob D.
>>
>>
>>
>>I have worked a lot on zugzwang detection in Tiger 15, and it has been improved
>>further in the new version (CT X). I think that's the answer. It's simply an
>>area I've been working on.
>>
>>
>>
>> Christophe
>
>Can I asume you belive there is quite a bit of extra strength to pick up for a
>chess engine fixing this problem? I belived this occured pretty rarely in most
>games.
>
>Torstein
Many pawns endgames are decided by very deep zugzwangs. These endgames are
generally not very interesting but human players excel at understanding them. So
I believe a substantial improvement is possible here for a chess engine.
Christophe
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