Many young hard throwing pitchers don't bother learning the change-up. The thinking is, if batters can't touch your heat, why slow down a pitch that they might be able to hit. Don't be fooled into thinking that.
“In high school I didn’t throw the change,” says Drabek. “My dad (Cy Young winner Doug Drabek) tried to get me to throw one. I couldn’t command it and I kind of just blew him off and did my thing. But once I got into pro ball, I started to realize that it might be the most important pitch you’ll ever learn to throw.” Kyle Drabek, Toronto Blue Jays
The changeup is a basic pitch that every pitcher learns at the lowest levels, because good hitters will catch up to a fastball sooner or later.
The theory behind a changeup is it comes with the same arm position and motion as a fastball, but is 10-15 mph slower based on the drag on the ball. And they make any fastball seem faster by comparison.
There are 2 basic changeups – the three-fingered changeup and the circle change.
The ball should be touching the “circle” on the thumb and index finger. It's thrown the same as a fastball.
As it is with all of pitching, keeping your intentions secret is a big part of the battle.
Keep the ball hidden in your glove when you're throwing, or you might tip off the batter (or a baserunner or base coach) what pitch you're throwing.
Wind up normally and throw. Don't forget to follow through. When you don't follow through, the ball will likely stay high. If your struggling to keep your changeup down, you want to almost exagerate your finish (follow through).