Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Mate in 1 - but Fritz 6 needs 1 hour!!!

Author: James Robertson

Date: 19:35:44 08/11/00

Go up one level in this thread


On August 11, 2000 at 01:27:40, Uri Blass wrote:

>On August 10, 2000 at 20:40:44, James Robertson wrote:
>
>>On August 10, 2000 at 17:46:30, Uri Blass wrote:
>>
>>>On August 10, 2000 at 17:22:58, Wayne Lowrance wrote:
>>>
>>>>On August 10, 2000 at 16:17:47, Christoph Fieberg wrote:
>>>>
>>>>>Unbelievable, but true:
>>>>>I composed a position which is mate in 1 and can easily found, but Fritz6 on
>>>>>Pentium III, 500 Mhz and 32 MB Hash needs more than 1 hour to show it (excatly
>>>>>1:03:17)!!!
>>>>>How do other computers react?
>>>>>
>>>>>The position is
>>>>>FEN: 8/8/pppppppK/NBBR1NRp/nbbrqnrP/PPPPPPPk/8/Q7 w - - 0 1
>>>>>
>>>>>It is possible to reach this position from starting position:
>>>>>1.Sa3 Sa6 2.Sc4 Sc5 3.Sa5 Sa4 4.b3 b6 5.La3 La6 6.Lc5 Lc4 7.h4 h5 8.Th3 Th6
>>>>>9.Td3 Te6 10.Td5 Te4 11.Sh3 Sh6 12.e3 e6 13.Le2 Le7 14.Lf3 Lf6 15.d3 d6 16.Ke2
>>>>>Ke7 17.Dd2 Lc3 18.Te5 Lb4 19.Th1 Td4 20.Lc6 Dd7 21.Lb5 Th8 22.Td5 Kf6 23.Sg1 Sg4
>>>>>24.Th3 Se5 25.Tg3 Kf5 26.Tf3+ Kg4 27.Tf5 a6 28.g3 c6 29.Sf3 Kh3 30.Sg5+ Kh2
>>>>>31.Se4 Sg6 32.Kf3 Se5+ 33.Kf4 Sg6+ 34.Kg5 Se5 35.a3 Th6 36.c3 Tf6 37.De2 g6
>>>>>38.Kh6 Sg4+ 39.Kh7 De7 40.Tf4 Tf5 41.Sg5 Df6 42.Df3 De5 43.Kg8 De4 44.Sh3 Tg5
>>>>>45.Tf6 Sh6+ 46.Kh7 Sg4 47.Df5 Kg2 48.Kg7 Sh2 49.De5 Tg4 50.Sg5 Sf3 51.Sh7 Sg1
>>>>>52.Df4 [52.Tf5 Se2 53.Sf6 Sf4 54.Se8 Kh2 55.Tg5 Kg2 56.Kh7 Kh2 57.Sg7 Kg2 58.Sf5
>>>>>f6 59.f3 Kh2 60.Kh6 Kh3 Test it! What time do computers need to reach a certain
>>>>>search depths?] 52...Se2 53.Df3+ Kh2 54.Tff5 Sf4 55.Dd1 Kg2 56.Tg5 Kh2 57.Sf6
>>>>>Kg2 58.Sg8 Kh2 59.Se7 Kg2 60.Sf5 Kh2 61.Da1 Kg2 62.f3 f6 63.Kh6 Kh3 Mate in 1!
>>>>>(64. Dh1#). What time do different programms need to show it in the display? 1–0
>>>>>
>>>>>52.Tf5 leads to a position with White Queen on e5 (instead on a1).
>>>>>FEN: 8/8/pppppppK/NBBRQNRp/nbbrqnrP/PPPPPPPk/8/8 w - - 0 61
>>>>>
>>>>>How long do computers need to reach for example depth 9?
>>>>>Fritz 6 reached depth 5 after 9 hours!! (on Pentium III, 500 MHz, 32 MB Hash) He
>>>>>showed 61. Dxe4 Txe4 62. dxe4 Lxc5 3. Txg4 hxg4 as best moves (+1.56 for White).
>>>>>What is the best move?
>>>>>
>>>>>Christoph
>>>>
>>>>nine hours to get to depth _five_ ? hard to understand. I think something is
>>>>wrong.
>>>
>>>It is very easy to understand.
>>>If a program does a lot of extensions it need 9 hours to get to depth 5.
>>
>>I will wager it is not even extensions, but just the qsearch that causes the
>>trees to explode.
>>
>>James
>
>Qsearch is one kind of extensions.
>
>Uri

A qsearch is a heavily pruned search....

James



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.