[Retros] 50-moves rule and mate
G.A.Rol at umcutrecht.nl
Tue Jan 16 13:28:38 EST 2007
I wrote my original analysis under the assumption (call it delusion) that the 50-moves rule was automatic. Since I can find no confirmation for this in source material I need a rethink on the whole subject. Having optional and preemptive claims complicates matters considerably but the ordering of evaluation rules, whether by claim or by automation, is always a relevant issue indeed.
> -----Oorspronkelijk bericht-----
> Van: retros-bounces at janko.at [mailto:retros-bounces at janko.at]
> Namens andrew buchanan
> Verzonden: dinsdag 16 januari 2007 16:59
> Aan: 'The Retrograde Analysis Mailing List'; pastmaker at aol.com
> Onderwerp: Re: [Retros] 50-moves rule and mate
> Hi Tom,
> Thanks for your interesting mail. You wrote:
> >under the FIDE rules for over-the-board play only the player on the
> >move can claim a draw. The checkmating move is unassailable
> under that
> >regime because the other player (i) is not on the move when the
> >checkmating move is played, and so must remain mute while
> the move is
> >played, and (ii) never regains the move, as the play of the
> >move ends the game.
> I agree with your conclusion that # trumps 50M (if it's the
> mated player who wants to claim), but I disagree with how you
> reach that conclusion.
> In order to know that it is #, you have to examine the new
> position, according to Art 1.2 ("The objective of each player
> is to place the opponent's king 'under attack' in such a way
> that the opponent has no legal move which would avoid the
> 'capture' of the king on the following move.")
> In this position, the possibly checkmated player already has
> the move. Firstly, because Art 1.1 says he does ("A player is
> said to 'have the move', when his opponent's move has been
> made.") Secondly, because in the new position you can't
> verify the legal moves correctly unless the right player has
> been assigned the move. Thirdly, note the use of the present
> tense in Art 1.2.
> Surely Guert Gijssen at Chess Café must have answered this
> question before? It's not really something we problemists
> should have to guess.
> (1) My reading is that stalemate and dead position are
> checked for at the same time as checkmate... just after the
> player has acquired the move, but before the new player can
> do anything.
> (2) I think Draw by Repetition is handled in the same way as
> 50M, and if it mattered (which I don't think it ever can in
> the game of chess because the situations are mutually
> exclusive) would be trumped by mate/pat/death.
> (3) But we've really only handled half of it. We were
> assuming that it was the mated player who wanted to claim the
> draw. In the weird world of composition, it could easily be
> the mating player who wants to claim the draw, in which case
> if we look at the Laws of the Game again, it is 50M which trumps #.
> (4) Now how does that affect chess compositions? The Codex
> doesn't give me adequate support to answer that question.
> The key point is that in the game, depending on who does the
> claiming, 50M or # may prevail. For this reason, it will not
> be so easy for Guus to craft a similar convention for 50M
> which worked to some extent for Rep.
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