Weighted Balls

It seems to me that for an 11-year-old, a standard baseball is already overload enough, since a baseball is designed to be thrown by adults, not by kids. When I pick up a rock or a snowball to throw, I instinctively choose one about the weight of a baseball. But when a kid picks up rocks and snowballs, he almost always goes for something lighter. Nature and experience tell him which weight he can throw most efficiently. Unless your son is very large and very strong, I'd be willing to bet that the heavier balls will cause subtle changes in his throwing mechanics.