How to win the baseball radar game?

I want a little insight as to where on the baseball radar game backstop to throw a fast pitch. It is not the guessing one, but one where you throw as fast as you can. I threw a pitch last night that could have struck out Bonds, yet it only registered 70. Then, a 5 year old steps up to the game, and lobs it at 49 mph. So, there has to be a trick in terms of placement of the pitch so I can throw it at 80 like I know I can, and get my throwback baseball jersey!