From: Jackie Meyer <fmeyer <at> ECE <dot> NEU <dot> EDU>
Date: 12 apr 2000
Subject: Re: Checkmate and other rules

On Wed, 12 Apr 2000, Pieter Stouten wrote:

> Back to checkmate: if neither player detects the mate and the mated
> player makes a move, then it is just an illegal move that is not
> detected.

Contrast this with the situation in western chess, where, if play
continues, the original result (mate) will stand if it is subsequently
detected, even if the game had already gone to completion with a different
result.

> As to George's rule 9 about changing the result of a game when a game
> has been written down, I am fairly sure that NSR states that the
> first event that ends the game determines the result:

I think this should say "that the first *claimed* event that ends the
game...."

> - mate
> - illegal move
> - resignation
> - exceeding time
> None of these takes priority. The chronology determines the result.

Fair enough, except that there is a concept of illegal moves becoming
erased on the board (whereupon their chronology no longer takes
precedence).

> Now, the issue of whether an illegal move should still be "detectable"
> on the board for a player to be able to claim a game is another issue.
> I would think NSR has an opinion on this and we should just ask them
> specifically. Since keeping score is not mandatory and score sheets
> have never received any official status,

However, in professional games, observers exist on the spot to confirm
that a move was illegal.  Amateur rules need to take into account the lack
of an observer.

> I would think they should not
> be permitted as evidence to claim an illegal move and the game.

The board is insufficient.  E.g., if I move a bishop like a rook, you will
need your score sheet to establish what the position was just prior to my
illegal move.  Professionals do not have to deal with this problem.

> As to swap-capture (i.e., bishop-takes-bishop by putting one's own
> bishop beside the board and turning the opponent's around; this
> really applies to any piece that captures the same type of piece,
> though), this *is* an illegal move (as confirmed by George Fernandez
> and Hugo Hollanders). It has been suggested to only issue a warning
> in such a case.

Akin to western chess, issuing a warning if one castles by moving the rook
first.

> But in my opinion issuing warnings is not the best way to approach the
> issue. It is principally wrong (after all, an illegal move is an
> illegal move) and it may lead to complicated, less-than-transparent
> rules

Again, we must take into consideration that we are dealing with amateur
shogi.  So, we must be prepared to indoctrinate players who are not
experienced at competitive play.

Regards,

Fred "Jackie" Meyer