The first rule of little league is: Keep your eye on the ball. The second rule of little league is: Keep your eye on the ball.
If you played as a youngster, then you heard the refrain over and over. The problem is,
you can't--at least not at the Major League level. When the ball approaches the plate it's simply moving too fast for the human eye to track. So hitters pick out where they expect it to be (which is trouble if you get a curve instead of a fastball).