Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: TestMate in 18: Announced in 1875 - Can your program find it?

Author: Uri Blass

Date: 00:27:05 03/05/01

Go up one level in this thread


On March 04, 2001 at 21:49:58, Steven J. Brann wrote:

>On March 04, 2001 at 12:49:05, Heiner Marxen wrote:
>
>>On March 04, 2001 at 08:24:38, Steven J. Brann wrote:
>>
>>>[D]2k1rbr1/1pp5/p3P1qp/1Q4p1/3P1p2/6N1/5PPP/R1B1R1K1 w - - 0 1
>>>
>>>This game was played by correspondence in 1875.  Mrs. Berry announced mate in 18
>>>from this position.  Can your computer do the same?  I doubt it.  CM8000 found a
>>>winning line in 18 moves (different than Mrs. Berry's), but wouldn't announce
>>>mate until 6 moves into the solution.  I'll post Ms. Berry's play and CM8000's
>>>line after you have a go at it.
>>
>>This one appears to be out of reach for Chest.  On my K7/600 (350 MB hash)
>>it needs already twenty minutes for "no mate in 8".  The effective branching
>>factor is around 8.  Provided, there is not a much shorter mate:  No chance!
>>
>>Now I'm waiting for the solution, to study it carefully!
>>
>>Heiner
>
>Here's the original mate and the CM8000 equivalent.  Enjoy

I tried to go forward and backward with yace under chessbase to check this
solution:
>
>{Mrs. Berry announces Mate in 18 from this position} 1. Rxa6 bxa6 2.
>Qxa6+ Kb8 3. Qb5+ Kc8 4. Qd7+ Kb8 5. Bxf4 gxf4 6. Qb5+ Kc8 7. Ra1 Ba3

Yace is calculating 7...Qb1+ after learning that 7...Ba3 is a mate against
black.

 8.
>Rxa3 Qb1+ 9. Qxb1 Rxe6 10. Ra7 Kd7

Yace prefers 10...Rc6 with evaluation of mate in 8 against itself that means
that the mate in 18 was right.

main line:10...Rc6 11.Ra8+ Kd7 12.Qf5+ Kd6 13.Rxg8 Rc1+ 14.Nf1 Rxf1+ 15.Kxf1
h5 16.Rg6+ Ke7 17.Qg6+ Kd8 18.Rg8#


>11. Qb5+ Rc6 12. d5

Yace suggests 12.Qd5+ as faster mate in this line

Uri



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.