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Subject: Re: Another Clever Problem; Samuel Loyd New York Albion 1857 (SPOILER)

Author: Daniel Clausen

Date: 09:51:00 03/06/02

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Hi

On March 06, 2002 at 11:56:02, Terry McCracken wrote:

[snip]


>That's the point, you _must_ assume when given a problem when the King is on
>it's initial square along with it's Rook or Rooks  that 0-0 or 0-0-0 is
>permissible.

Not at all. If you give a FEN string, all that counts is the FEN string. If the
FEN string is broken, the problem is broken. If the FEN string indicates
castling is possible, then castling is possible, otherwise it isn't.

If all you give is the board and castling might be possible (ie both king and
rook(s) on initial squares) you have to solve the problem (ie mate in X) for
both cases. The fact that newspapers (and many chess books too) _assume_
something doesn't mean a thing. There are also problems where the author wants
you to check both possibilities. (ie "the Chess Mysteries of Sherlock Holmes" by
Raymond Smullyan - a fantastic books if you're interested in retro-analysis btw)
One of the problems in the mentioned book is a position (_without_ a FEN string)
where the problem is to prove that this position is mate in X, although it's not
possible to actually _show_ the mate. The idea is that the position is mate in
X, whether castling is possible or not, but the actual moves in these cases
differ. And since it's not known whether castling is allowed or not, all you can
say is that it's mate in X. (hope I made some sense here, heh!)

Note: If you use the FEN string in this forum only in order to paint a fancy
diagram, you can always make a lil remark saying, that we should ignore the FEN
string and only watch at the diagram. Of course saying this often gives a clear
hint as to what the idea behind the problem is.

Sargon



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