Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Interesting Position Mate in 15

Author: blass uri

Date: 11:35:40 01/12/00

Go up one level in this thread


On January 12, 2000 at 13:41:29, m.d.hurd wrote:

>On January 12, 2000 at 12:09:08, John Merlino wrote:
>
>>On January 11, 2000 at 22:15:50, Imran Hendley wrote:
>>
>>>On January 11, 2000 at 20:06:00, John Merlino wrote:
>>>
>>>>On January 11, 2000 at 03:11:42, m.d.hurd wrote:
>>>>
>>>>>On January 11, 2000 at 03:07:19, m.d.hurd wrote:
>>>>>Correction :
>>>>>
>>>>>Fritz 6 solves this in seconds and keeps announcing the mate up to where it
>>>>>promotes to a knight then draws by three fold repitition.
>>>>>
>>>>>
>>>>>Start position
>>>>>
>>>>>[D] 8/8/8/2p5/1pp5/brpp4/1pprp2P/qnkbK3 w - - 0 1
>>>>>
>>>>>Regards
>>>>>
>>>>>Mike
>>>>
>>>>Chessmaster falls into the same trap as Fritz (et. al.). It announced mate in 15
>>>>in 8 seconds (on a PII-450), and proceeded to promote to a queen for a 3-fold
>>>>draw.
>>>>
>>>>But, if I take it past the knight promotion, it DOES work out the mate in 9 from
>>>>there.
>>>>
>>>>jm
>>>
>>>I don't see the logic behind this. When it announces mate does it see the knight
>>>promotion? If so why does it promote to a Queen? And if when it announces mate
>>>it sees a Queen promotion, how can this be, because there is obviously no mate
>>>with a Queen. Do you know why this happens?
>>
>>I have no idea why it happens. It does appear to defy logic. But there must be
>>SOME programmatic reason for it, since Fritz appears to do its own version of
>>the same thing (announce mate, promote to knight, draw by 3-fold).
>>
>>jm
>
>And not just Fritz 6, if you take the position after the pawn has promoted to a
>Knight, neither Fritz 6 or 5.32 or Hiarcs 7.32 or Crafty 17.4 find the mate.
>Doctor 3 does and also comet b10. So some solve it and some do not, maybe
>someone else knows the answer why it should be so difficult.
>
>Mike

The logic is that some programs do assumptions that king and knight with no more
pieces cannot win.

Fritz is alsoa root processor so it does this assumption only when white has
only king and knight in the root position.

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.