From: "Dr.Eduard Werner" <edi.werner <at> GMX <dot> DE>
Date: 5 mar 2001
Subject: Re: not promoting rook or bishop? (about Sam Sloan HP)

>   Can anyone give me a sample position in
> which one should better not promote Rook or
> Bishop. I just can't believe it. (Well, if it
> wasn't Sam I'd actually discarded it yet).
>
>   I can't understand how can an unpromoted
> rook or bishop do just anything their
> promoted versions can't (being their
> movement pattern a superset of the original
> ones).

I think for any Shogi Variant w.o. drops you're absolutely right.
I can't think it can be an advantage say, in Chu, not to promote
a B or an R. In Modern Shogi, however, the promoting of the R or
the B might take an additional square from the opponents K so that
you can't drop a P the next move because it would be mate. For a tsume,
you might *need* an uncontrolled square your opponent's K can move to.
I can't give you a position, but the idea would be:

R moves with check into promotion zone  K moves out of check
P gets dropped in front of K    K moves next to R
some tricky tsume to follow

With a promotion on the first move, this would not be possible as the
K could not move next to the R, so the P drop would be illegal.

Best

Edi