H. G. Muller wrote on Sun, May 31, 2020 02:39 PM UTC:
Move induction
In Knight-relay Chess a Knight induces extra Knight moves in friendly pieces that are a Knight jump away from it. In the Interactive Diagram I used an ad-hoc extension to the move description to indicate such a thing, by considering the induction step (from inductor to induced piece) plus the induced move as a single multi-leg move. The first leg of this move then carried an 'x' modifier, indicating that it wasn't a real move, but just an interaction that 'excited' the target to make the step described in the following leg(s). In XBetza notation, where legs are separated by 'a', this would be xaN. So far so good.
But in Odin's Rune Chess, the King doesn't have a move of its own, but can move as any of the adjacent friendly pieces. To describe that with move induction would be awkward; every non-royal piece must be an inductor, but they would not induce their move on any piece, just on the King. They would be selective move inductors, and so far XBetza has no device to specify such selectivity.
But then it dawned on me that I was looking at this from the wrong perspective. The non-royal pieces in Odin't Rune Chess are not (selective) move inductors, but it is a universal property of the King, which is a move borrower. If we could define a move descriptor for that, it would only have to be applied to the King, and would not have to be type-selective.
Fortunately the same 'x' can be used to indicate this, by strapping it on the final leg of a multi-leg move (or on a simple move); its use in move induction will always be in a non-final leg, as the induced move must follow. So if no move follows an x-leg, it can be taken to mean reverse excitation, from target to source, instead of from source to target. The King in Odin's Rune Chess would then be fully described by the XBetza notation xK: borrow moves from pieces a King step away.
I wonder if this system is universal enough to handle most cases of move induction that occur in CVs. Are there any other variants that use move induction? I only know of Scirocco, where the Dervish, and its promoted form the Harpy, are universal move inducers similar to the Knight in Knight Relay Chess.
Move induction
In Knight-relay Chess a Knight induces extra Knight moves in friendly pieces that are a Knight jump away from it. In the Interactive Diagram I used an ad-hoc extension to the move description to indicate such a thing, by considering the induction step (from inductor to induced piece) plus the induced move as a single multi-leg move. The first leg of this move then carried an 'x' modifier, indicating that it wasn't a real move, but just an interaction that 'excited' the target to make the step described in the following leg(s). In XBetza notation, where legs are separated by 'a', this would be xaN. So far so good.
But in Odin's Rune Chess, the King doesn't have a move of its own, but can move as any of the adjacent friendly pieces. To describe that with move induction would be awkward; every non-royal piece must be an inductor, but they would not induce their move on any piece, just on the King. They would be selective move inductors, and so far XBetza has no device to specify such selectivity.
But then it dawned on me that I was looking at this from the wrong perspective. The non-royal pieces in Odin't Rune Chess are not (selective) move inductors, but it is a universal property of the King, which is a move borrower. If we could define a move descriptor for that, it would only have to be applied to the King, and would not have to be type-selective.
Fortunately the same 'x' can be used to indicate this, by strapping it on the final leg of a multi-leg move (or on a simple move); its use in move induction will always be in a non-final leg, as the induced move must follow. So if no move follows an x-leg, it can be taken to mean reverse excitation, from target to source, instead of from source to target. The King in Odin's Rune Chess would then be fully described by the XBetza notation xK: borrow moves from pieces a King step away.
I wonder if this system is universal enough to handle most cases of move induction that occur in CVs. Are there any other variants that use move induction? I only know of Scirocco, where the Dervish, and its promoted form the Harpy, are universal move inducers similar to the Knight in Knight Relay Chess.