nabla: One more question - is this game played with pawn promotions? And if so and a promoted pawn is captured, can it be recycled as the promoted piece or does it turn back to a pawn?
Fencer: Yes, at least the last time I played with the inventor we played with promotions. We didn't have the case of a promoted piece being taken, I don't see why it should revert to a pawn (except for being bughouse-like), but I can ask him what he thinks about it.