You couldn't add chips at the Knees and belt line... Players would constantly be pulling chips up and down 3 or 4 inches.... If you wanted to do it, all you would need to do is base the strike zone on height, when a player comes to bat a system picks out his strike zone from a data base... and that's his strike zone. I don't know if I would favour such a system... Put it would be fun to see it work.