Jörg Knappen wrote on Tue, Oct 2, 2012 03:14 PM UTC:
Here's an idea how to switch on the can-mate property without changing the moves of a given piece:
Can-mate Knight: Moves and captures as a normal FIDE Knight; but when the endgame KN vs. lone K is reached, it gives immediate check (and checkmate, if the lone King cannot capture it).
Switching off the can-mate property is not so easy. Just defining a Cannot-mate Rook as normal Rook, but when the endgame KR vs. lone K is reached, it it automatically a draw, unless the last capture gives checkmate -- seems to work, but in practice the stronger side will be keen to keep a pawn or two on the board and perform the mate with the full Rook before it is too late.
Can-mate Knight: Moves and captures as a normal FIDE Knight; but when the endgame KN vs. lone K is reached, it gives immediate check (and checkmate, if the lone King cannot capture it).
Switching off the can-mate property is not so easy. Just defining a Cannot-mate Rook as normal Rook, but when the endgame KR vs. lone K is reached, it it automatically a draw, unless the last capture gives checkmate -- seems to work, but in practice the stronger side will be keen to keep a pawn or two on the board and perform the mate with the full Rook before it is too late.