Am I correct in thinking that winning for white is not a given with best play? Eg example one, black king on f7 and white king on f5, with white winning opposition, black can simply drop back to f8 and white king cannot move forward else stalemate can be forced. So black can flip between f7 and f8 except if the white king moves forward to 6th rank and black king then takes opposition on 8th rank forcing the king back or stalemate. Am I missing something?