Two related questions:hgm wrote:Gating moves are written as promotions. (There never is any ambiguity, as Pawns are not allowed to gate, and even if they would, a virgin Pawn cannot promote.) So you would write f1g3e to gate the Elephant at f1. In SAN WinBoard now accepts both = and / in gatings and true promotions, and writes = with promotions and / with gatings. The ICS writes = for both, however.
1. When castling, you can gate one piece to either the original square of the king, or the original square of the rook (from Wikipedia). How do you specify which one it is? Plain "e1g1h" is ambiguous.
2. How do you do this in the GUI? I know to select the piece from holdings before the move, but how do I get it to go to the rook's square when castling?
EDIT: ah, I see you posted that information while I was typing this. Good.
That seems reasonable.This info seems to make the castling field superfluous, and could perhaps replace it.
Ditto.Reinhard proposed two hex numbers separated by a period, representing a bitmap of the virgin pieces, like
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR [HEhe] w FF.FF - 0 1
I am not so keen to use hexadecimal in FEN, though.
The strength of FEN is that it is easily readable for humans, and this would be lost by including hexadecimal numbers. Plus, it wouldn't generalise to variants on a large board that include gating.
This is a generalisation of the FRC FEN castling flags, and makes sense to me. I think this is the best option.A alternative would be to append the file letters of non-virgin pieces still in their original position to the castling field. (In practice there are never many of those).
(But maybe I'm biased because this is what Sjaak does internally anyway)
Consistency (with respect to other variants implemented now as well as other variants that may be added in the future) is the important question here, I think. Either is fine, as long as it's clear.Another, more general issue is if it is really desirable to use H and E for pieces that in other variants are called A and C.
Perhaps consistency with XBoard is the most obvious choice.
Unrelated question: are you planning a Seirawan tournament at some point in the future?
I ask, because if so there are some changes I need to make to Sjaak (straightforward changes, but still); it currently can't store castle+gate moves.