You can usually determine the height of the ball from the time you send it towards the building. This gives you a very brief amount of time to judge its trajectory and decide when will be the exact time to jump. You can never get a ball so low that it hits the caveman's feet. If you think it will be a low ball, still jump when it is very close just to be safe.

When the ball hits the creeping monster that appears occasionally, it changes directions. The height of the ball will be different, making it necessary for you to be ready to execute a quick jump.