💡📝H. G. Muller wrote on Tue, Apr 27, 2021 09:25 AM UTC:
Standard notations for castling cannot deal with such ambiguity. An alternative notation that is used in UCI protocol is KxR (e.g. e1h1 or Kxh1 for O-O in orthodox Chess). But this would be problematic in the context of a very general system, where capture of a friendly piece might be allowed. Furthermore, the KxR notation is sometimes also used for resolving ambiguity between castling and normal King moves, in games with flexible castling, to indicate the castling where the King makes a single step (i.e. O1 castling).
Your variant poses the problem that both the King destination and the castling partner have multiple options. This requires specification of two squares. A possibility would be to let the empty square where the King should move to capture the Rook. (Or have the castling partner capture itself, when the King would end there.) Perhaps Greg has ideas of how to best solve this.
BTW, I seriously wonder how the castling choice that you propose can be any good: castling was invented for bringing the King to safety without trapping the Rook. If you can castle with an 'inner' piece through the jO castlings, you would trap the outer piece. Unless that piece can develop by jumping over the Pawn shield (as it can in Omega Chess). But then castling with it serves no purpose. You would have to get rid of the inner piece first before the second becomes available for castling. And if that inner piece is a Rook, you wouldhave to compromise the Pawn shield for that, in such a way that you would not want to castle in that direction anymore. While when both the corner piece and the inner piece were capable of jumping over the Pawns, involving them in a castling serves no purpose. In that case the only beneficial effect is to speed up the travel of the King towards a corner. But you could have achieved that by just giving the King an isR move.
Standard notations for castling cannot deal with such ambiguity. An alternative notation that is used in UCI protocol is KxR (e.g. e1h1 or Kxh1 for O-O in orthodox Chess). But this would be problematic in the context of a very general system, where capture of a friendly piece might be allowed. Furthermore, the KxR notation is sometimes also used for resolving ambiguity between castling and normal King moves, in games with flexible castling, to indicate the castling where the King makes a single step (i.e. O1 castling).
Your variant poses the problem that both the King destination and the castling partner have multiple options. This requires specification of two squares. A possibility would be to let the empty square where the King should move to capture the Rook. (Or have the castling partner capture itself, when the King would end there.) Perhaps Greg has ideas of how to best solve this.
BTW, I seriously wonder how the castling choice that you propose can be any good: castling was invented for bringing the King to safety without trapping the Rook. If you can castle with an 'inner' piece through the jO castlings, you would trap the outer piece. Unless that piece can develop by jumping over the Pawn shield (as it can in Omega Chess). But then castling with it serves no purpose. You would have to get rid of the inner piece first before the second becomes available for castling. And if that inner piece is a Rook, you would have to compromise the Pawn shield for that, in such a way that you would not want to castle in that direction anymore. While when both the corner piece and the inner piece were capable of jumping over the Pawns, involving them in a castling serves no purpose. In that case the only beneficial effect is to speed up the travel of the King towards a corner. But you could have achieved that by just giving the King an isR move.