💡📝H. G. Muller wrote on Wed, Apr 28, 2021 08:30 AM UTC:
In Odin's Rune Chess (or Chu Shogi) the hit-and-run captures use notations like Fxh5-g4, while double captures are written as Fxh5xg5. (The interactive diagram, unlike the automatically generated presets for Game Courier, doesn't make a distinction between 'shooters' and double movers, so the extra victim of the Forest Ox should be entered and is written as an intermediate square.) But this only accounts for double-moves with the same piece, and castling doesn't fall in this class.
I guess the most natural notation for castlings for which O-O and O-O-O would be ambiguous is indeed as a double move. But now that I think about it, the fact that there is both jO castling (with the Rook) and O castling (with the Cannon) doesn't really cause any ambiguity: you can only castle with the nearest piece. The only problem here is the usual one for free castling, that you need to specify the King destination. It is sort of standard to make a sideway King move of more than one step imply castling in that case. In any case, O-O noation is no good for free castling. So I suppose I should make the diagram recognize the case where a piece has multiple O moves in the same direction and the same partner with different range. And in that case use the King's move for notation rather than O-O.
There still is the issue for how to distinguish O1 castling from an ordinary King move, and how to handle the case where the King ends on the Rook square. The KxR notation seems natural for the latter case, as it would indeed specify the square where the King ends. (There still is no need to specify the Rook move separately; it is fully implied.) But then KxR would not be available for O1. RxK doesn't seem such a bad way for indicating O1 castling, as you would specify a Rook move with a square where the Rook indeed ends up.
How about using a special separator for castling? We now have x for captures, and - (or nothing) for non-captures. We could adopt ~ for castling. So in the orthoChess setup Kd1 or K-d1 would be a normal King move to (empty) d1, but K~d1 would be Q-side O1 castling. K~h1 would be K-side O3 castling.
In Odin's Rune Chess (or Chu Shogi) the hit-and-run captures use notations like Fxh5-g4, while double captures are written as Fxh5xg5. (The interactive diagram, unlike the automatically generated presets for Game Courier, doesn't make a distinction between 'shooters' and double movers, so the extra victim of the Forest Ox should be entered and is written as an intermediate square.) But this only accounts for double-moves with the same piece, and castling doesn't fall in this class.
I guess the most natural notation for castlings for which O-O and O-O-O would be ambiguous is indeed as a double move. But now that I think about it, the fact that there is both jO castling (with the Rook) and O castling (with the Cannon) doesn't really cause any ambiguity: you can only castle with the nearest piece. The only problem here is the usual one for free castling, that you need to specify the King destination. It is sort of standard to make a sideway King move of more than one step imply castling in that case. In any case, O-O noation is no good for free castling. So I suppose I should make the diagram recognize the case where a piece has multiple O moves in the same direction and the same partner with different range. And in that case use the King's move for notation rather than O-O.
There still is the issue for how to distinguish O1 castling from an ordinary King move, and how to handle the case where the King ends on the Rook square. The KxR notation seems natural for the latter case, as it would indeed specify the square where the King ends. (There still is no need to specify the Rook move separately; it is fully implied.) But then KxR would not be available for O1. RxK doesn't seem such a bad way for indicating O1 castling, as you would specify a Rook move with a square where the Rook indeed ends up.
How about using a special separator for castling? We now have x for captures, and - (or nothing) for non-captures. We could adopt ~ for castling. So in the orthoChess setup Kd1 or K-d1 would be a normal King move to (empty) d1, but K~d1 would be Q-side O1 castling. K~h1 would be K-side O3 castling.