Good point. I did not give much thought to the end-game, as I beleived the game would almost always be decided in the middle game, due to the material superiority of the attacker. But this is a needless flaw; I can add the condition that the pieces can check from anywhere, even if they cannot make other captures. That doesn't really improve their strength as defenders, as a King will never be amongst the attackers in the middle-game.
Good point. I did not give much thought to the end-game, as I beleived the game would almost always be decided in the middle game, due to the material superiority of the attacker. But this is a needless flaw; I can add the condition that the pieces can check from anywhere, even if they cannot make other captures. That doesn't really improve their strength as defenders, as a King will never be amongst the attackers in the middle-game.
Thanks for raising this point!