There is also a set of world-histories satisfying (drop ball) which is distinct from the set of world-histories satisfying NOT(drop ball). Of course, by throwing this piece of world model out the window, and only allowing to compensate for its absence with measures, you do make measures indispensable. The problem with what you were saying is in the connotation, of measure somehow being the magical world-modeling juice, which it's not. (That is, I don't necessarily disagree, but don't want this particular solution of using measure to be seen as directly answering the question of predictability, since it can be understood as a curiosity-stopping mysterious answer by someone insufficiently careful.)