Author: Richard A. Fowell (fowell@netcom.com)
Date: 13:54:59 03/12/00
Go up one level in this thread
On March 12, 2000 at 16:43:50, Heiner Marxen wrote:
>On March 12, 2000 at 15:54:16, Robert Hyatt wrote:
>
>>On March 12, 2000 at 15:39:57, John Coffey wrote:
>>
>>>[D]1Q6/K7/8/3k4/8/8/8/8 w - -
>>>
>>>I had this position in a game and I wondered what the shortest route to mate
>>>is. I have seen methods by which one advances the king first and other methods
>>>where one advances the queen first.
>>>
>>>I think that Qf4 might be the best move although I can't prove it.
>>>
>>>I gave the problem to Fritz6 thinking that it would either know the answer
>>>immediately or would be able to find it quickly. After some searching it came
>>>up with mate in 31, but after playing a move or two it quickly turned into mate
>>>in 9.
>>>
>>>After searching several hours Fritz came up with Qb4 mate in 26. I don't know
>>>if that is the fastest solution since I have heard that one can mate with this
>>>in less than 20 moves.
>>>
>>>John
>>
>>Here is the right answer:
>>
>>White(1): egtb !
>>1. Qf4! Kc5 2. Qe4 Kb5! 3. Qd4 Ka5 4. Kb7! Kb5! 5. Kc7! Ka5! 6. Kc6!
>>Ka6! 7. Qb6#
>>
>>Obviously a mate in 7. Moves with a ! after them are the _only_ move that
>>provides the best resistance (all other moves there result in a shorter
>>mate).
>>
>>(the above is output from Crafty).
>
>Just a remark regarding the exclamation mark notation: the moves
>4... Kb5 and 6... Ka6 are the only legal moves for black in the
>respective positions. Therefore I would like to not mark them with an
>exclamation mark, since they are better than all others simply
>because there are no others. If there is an annotation for
>"the only legal move" I would use that. In PGN I find just 2 NAGs
> 7 forced move (all others lose quickly)
> 8 singular move (no reasonable alternatives)
>which do not quite fit.
>
>Would others object? Suggestions for a new annotation?
>
>Heiner
Hmmm.
Forced moves could be annotated as : (duh!)
but that's both lengthy and a bit insulting.
You can send email to Steve Edwards suggesting a new NAG for the next
version of PGN.
As far as a symbol goes, I don't know Perhaps a lowercase greek phi,
which is often used to represent the null set, which is the set
of alternatives, here.
Richard A. Fowell (fowell@netcom.com)
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