H. G. Muller wrote on Tue, Sep 23, 2014 08:09 AM UTC:
Although the proposed Betza 2.0 notation allows one to describe almost any complex move, even castlings or catapult pieces, the descripton easily gets very long and cumbersome. And the power of Betza notation is its compactness, which is achieved by choosing good defaults, coinciding with the needs of the common case. The vast majority of pieces in Chess variants is totally symmetric, so that an atom by default means 'all symmetry-equivalent moves with this stride' makes that you almost never have to go into the complexity of writing directional modifiers, and the rarity of divergent pieces means you almost never have to write explicit modalities m or c, as mc is taken as default.
So it would be nice to have some 'convenience notation' for very common cases that in the formal system would need a complex expression. Just like Q is a convenient shortcut for W7F7 (or WWFF). And the most common cases are of course castling and e.p. capture; most variants have those.
Now that I am actually implementing a method for engines to inform the WinBoard GUI on how the pieces occurring in a variant move (so that the GUI can do legality testing, highlight target squares of a picked up piece and make sensible move notation), by sending the moves in Betza notation, I noticed how important that is. As with everything, you have to start simple, but in original Betza notation there were no provisions for e.p. and castling. So I want to propose the following shorthands that don't need the complexity of chaining that is the heart of Betza 2.0:
(1) 'e' is an new modality modifier next to 'm' and 'c', meaning e.p. capture. The latter is defined as capture of the piece the opponent just moved with an initial move (which was prefixed with 'i' modifier), by moving to the square that it just skipped. E.g. FIDE Pawns would have an ifmnD (=initial forward non-jumping Dabbaba non-capture move), and the combination i&n here triggers the creation of an e.p. square (namely the square where the move could have been blocked). A move feF on the Pawn would allow it to move to that e.p. square, removing the previously moved piece from the board. This would make: FIDE Pawn: fmWfceFifmnD Berolina Pawn: fmFfceWifmnA
(2) 'O' is not an original Betza atom, but many extensions use it as null-move. As such, any repetition of it, like O2, would be pointless, as would be any modifier prefixes. I therefore propose to use O + number as a shorthand for (conventional) castling. (After all, castling in PGN is denoted as O-O or O-O-O.) The number would indicate how many steps the King moves. The move of the Rook (or in general, the corner piece) is implied: it ends up next to the King on its other side. Also implied is that you cannot move through or out of check, and that all squares between King and corner have to be empty. So the full description of a King would be FIDE: WFisO2 Capablanca: WFisO3 (The rule that all squares between King and corner should be empty implies a non-capture. I guess the 's' could be implied too by making it default; 'l' or 'r' explicit modifiers would make sense, however, for asymmetric castlings like in Janus Chess.)
Although the proposed Betza 2.0 notation allows one to describe almost any complex move, even castlings or catapult pieces, the descripton easily gets very long and cumbersome. And the power of Betza notation is its compactness, which is achieved by choosing good defaults, coinciding with the needs of the common case. The vast majority of pieces in Chess variants is totally symmetric, so that an atom by default means 'all symmetry-equivalent moves with this stride' makes that you almost never have to go into the complexity of writing directional modifiers, and the rarity of divergent pieces means you almost never have to write explicit modalities m or c, as mc is taken as default.
So it would be nice to have some 'convenience notation' for very common cases that in the formal system would need a complex expression. Just like Q is a convenient shortcut for W7F7 (or WWFF). And the most common cases are of course castling and e.p. capture; most variants have those.
Now that I am actually implementing a method for engines to inform the WinBoard GUI on how the pieces occurring in a variant move (so that the GUI can do legality testing, highlight target squares of a picked up piece and make sensible move notation), by sending the moves in Betza notation, I noticed how important that is. As with everything, you have to start simple, but in original Betza notation there were no provisions for e.p. and castling. So I want to propose the following shorthands that don't need the complexity of chaining that is the heart of Betza 2.0:
(1) 'e' is an new modality modifier next to 'm' and 'c', meaning e.p. capture. The latter is defined as capture of the piece the opponent just moved with an initial move (which was prefixed with 'i' modifier), by moving to the square that it just skipped. E.g. FIDE Pawns would have an ifmnD (=initial forward non-jumping Dabbaba non-capture move), and the combination i&n here triggers the creation of an e.p. square (namely the square where the move could have been blocked). A move feF on the Pawn would allow it to move to that e.p. square, removing the previously moved piece from the board. This would make: FIDE Pawn: fmWfceFifmnD Berolina Pawn: fmFfceWifmnA
(2) 'O' is not an original Betza atom, but many extensions use it as null-move. As such, any repetition of it, like O2, would be pointless, as would be any modifier prefixes. I therefore propose to use O + number as a shorthand for (conventional) castling. (After all, castling in PGN is denoted as O-O or O-O-O.) The number would indicate how many steps the King moves. The move of the Rook (or in general, the corner piece) is implied: it ends up next to the King on its other side. Also implied is that you cannot move through or out of check, and that all squares between King and corner have to be empty. So the full description of a King would be FIDE: WFisO2 Capablanca: WFisO3 (The rule that all squares between King and corner should be empty implies a non-capture. I guess the 's' could be implied too by making it default; 'l' or 'r' explicit modifiers would make sense, however, for asymmetric castlings like in Janus Chess.)