I want to add something, your young 14. Chances are you won't play teams with good batters. When I mean good batters, the ones who can wait on a slow pitcher and drive a pitch the other way or can catch the fast guys and take it center or to left, RHB. Your probably going to face a majority of kids that have one basic swing. To pull everything to left or right up the middle. Ok, lets use our brains here. We'll start with example 1. Your a good pitcher, throw heat for your age and can really blow it by someone. Now this is for those hitters I talked about the ones that don't adjust well. If you can blow it by. Go with the inside corner. If you hit the inside corner if he does make contact and he is behind you then he'll have a weak grounder probably not a good hit especially if he's behind. Now say you throw one outside corner. He's going to have the same swing, behind your pitch but instead of a weak dribbler he might take it to right field. He did exately what he's supposed to but not on purpose. Outside ptiches are supposed to be waited on and hit farther back. Since your fast you just did that for him. You allowed him to wait (not on purpose though) on a pitch and hit it the other way.
Situation 2. Your a slower pitcher and most guys are ahead of you. Instead of pitching to the inside move on the outside and force them to wait on you and hit it to right. If your slow and throw it inside even though the batter is jumping out ahead of the pitch, its doing no harm because he's ahead of it like he should. Now say you throw outside corner. Now if he's ahead of it and pulls it, unless he gets ahold of it real good he's going to hit it to the left side of the infield hopefully for an out.
DISCLAIMER: This isn't full proof and doens't mean you should pitch to only one corner. You do need to use both but consider trying this out especially earlier in a game when they might not be used to you. Once they catch on you'll have to change it up a bit. And hopefully you have good offspeed stuff to compliment this. I would bet that if you did this to a freshman or JV team you can get out of 3 innings with throwing only fasbtalls. If you can locate them.
Also this is tricky against varisty players once you start playing good hitters that adjust their first at bat the chance of this working goes down.