When I realized I was never going to be a Feller or a Raschi or a Gibson or a Verlander, to name four fireballers, I went the other way and became a snake-jazzer—and a very good one. Welcome to the club!
By all means, talk to your coach about adding a few extra pitches to your repertoire. I would strongly suggest, however, that when it comes to the slider you get in touch with a professional pitcher who throws (or threw) a good one; there have been so many instances of injuries resulting from improper instruction in how to throw this pitch, too many people relying on all sorts of abstruse technologies and what not. What Ed Lopat told me was simplicity itself: “Throw it like a curve, but roll your wrist, don’t snap it”—and he showed me the off-center grip he used and demonstrated the wrist action, then handed me the ball and told me to go ahead and try it. I got the hang of it in about ten minutes, and I had a new pitch to work on over the winter.
Oh yeah—be sure to learn a good changeup or two. Babe Ruth, who knew a thing or two about pitching, once said that a good changeup will cause batters more grief than just about anything else! The other day I was watching the Yankees on TV, and I saw Joba Chamberlain make several hitters look very stupid with a good changeup.
Any more questions, I’m here. 8)