I think, that even with the present rules there is still the possibility to draw if both players are equal in pieces and none of them want to attack (or to make a senseless attack). If one of the players has an advantage in material after the middle game, he should IMHO win. It means: There would be probably more draws with the Alfonso's rules. There is a lot of draws in chess or checkers - so what? Playes who can't or don't want to see a draw and want to play forever to make their opponent tired are not worth playing with. :-)