Yes, predictions can greatly improve recognition performance. Not only can you focus the bulk of your computations on the expected region of interest, but you can also potentially reason about appearance (e.g., if you know the frame-rate/integration time of the camera and expected speed of the ball, you could get estimates about how much blur to expect). You could also better handle difficult cases, such as when balls strike each other (e.g., simple conservation of momentum estimates should greatly constraint possible hypotheses for ball positions).
