From: "Jeroen J.-W. Tiggelman" <CRMBJTI <at> HDETUD2 <dot> TUDELFT <dot> NL>
Date: 16 apr 1996
Subject: Re: Checkmate

> OK, my two cents. This discussion baffles and amazes me. As far as I can see
> from the letters pouring in, we do not even have a consensus about whether
> or not the pawn drop in the original position is legal or not. My thoughts:

Yes, it seems we have no consensus.

> "mate" in books, I always assumed that a pawn drop was illegal if it created
> a situation which I will now call the "opponent's king inevitably being
> captured next move". My understanding of this is that in the original
> example it is not legal to drop.

I am inclined to opt for that explanation as well.

> If you define mate in this way, everything becomes very clear. I do not
> understand this about there being no mate in shogi. Since there is such a
> rule regarding pawn drops, ergo the concept of mate exits, or?? Maybe kings
> can be taken in practice, but that seems to be another matter entirely.

The rules as I know them indeed use the term "mate". But I am unsure
whether this is the way they were explained originally, or a
westernized restatement. Just an observation. :-)

> legal position and the game continues. I can think of dozens of reasons to
> bash chess as a comparative game, but hardly on the grounds that it has a
> clear set of rules... but maybe Arnoud just wants to take kings. (I think it
> is often allowed in blitz, no?)

I agree. In fact Arno's explanation didn't seem correct to me at all.
(And yes, I thought usually it was.)

> The fact that this discussion is so complex here is rather frightening, and
> raises to my mind my first real feeling of drawbacks with shogi - this
> certainly is a situation that can occur often, and I find it incredible that
> there is no rule to clarify it. I would guess there is (?).

I am less sure of this. My understanding is that it is not felt as
obligatory in the east to formalize rules, but instead that in case of
a problem one refers to an older player who comes up with a suitable
resolution of the problem. Then again, I would think that this problem
in particular must have been considered many times before, so...

> Finally, again to weave chess into it, there is often a similar gray spot
> for less experienced players while playing - they will try to deliver "mate"
> with, for example a pinned piece, or get out of mate by capturing with their
> king a piece protected by a pinned piece. This misconception is cleared up
> by the argument that it doesn't work because one's king would be taken first
> (if one could take kings).

I think this is where Reijer feeling comes from that the rule is not
in accordance with the rest of the game concept: there is no such
obvious explanation why the move is disallowed, it seems somewhat
discontinuous.

> It may be that a kind of reverse effect is setting in here? That the drop
> (in the original query) is legal because the pinned piece can capture since
> kings are occasionally taken, when in fact it is not because there is a
> concept of mate occuring first?

Something of the kind, yes, I believe so. What is missing is a logical
explanation why the mating-pawn-drop is prohibited. :-)

> Was that clear?

To me it was.

> Jonathan Tisdall

Jeroen Tiggelman
crmbjti <at> hdetud2 <dot> tudelft <dot> nl