Watch the reaction of the batter to a pitch.. this is valuable.
Say that you throw a ball outside the zone, and in, and the batter has one of those RIDICULOUS swinging strike animations (where they nearly fall over, the ones that are just awesome)... That's because he was aiming to the outside part of the plate, or vise versa. When they really stretch to hit a ball and they have that stretching animation, it's because they're aiming to the inside part of the plate. Remember that and continue to throw where you did, because they usually tend to aim for the part of the plate that they were original aiming for. You don't want to get too predictable, but it works. It works in the inverse too ... say that you throw inside and the guy has a swinging strike that's really pathetic (where they almost fall over), if you go outside on the next pitch, be prepared to have that ball hit out of the park, because he's aiming over there.
If a batter is really swing happy, it's probably because you're throwing it into the zone that he's aiming.
If a batter is behind a pitch, he's probably expecting a breaking ball or changeup, and you threw a FB... so throw another FB. If he's ahead of the pitch, he was expecting a FB and you threw a breaking pitch, so throw another breaking pitch.
It's pretty cool, you really have to get into headgames with the opposing batters.
I always try to think of where the guy is swinging and when he's swinging when I throw a certain pitch. One of the keys is seeing what he's looking for. If you throw a Fastball and he's behind the pitch, he's looking for a breaking pitch or a changeup, so you should throw another fastball to keep him off.
If you throw a breaking ball and he's in front of the pitch, throw another breaking ball, because he's going to be swinging ahead again.
I try to see where they're swinging and stuff... if they are swinging at a lot of balls on the outside part of the plate, I am hesitant to throw them a pitch in the zone on the outside part of the plate because they'll be apt to swing and possibly lay some lumber on it.
