What I’m seeing here is a lot of confusion and a lot of misinformation regarding the slider, the curveball and breaking pitches in general. So let me put my 75 cents’ worth into the discussion.
When I learned the slider, my pitching coach—an active major league pitcher who threw a very good one—told me, “Throw it like a curve, but roll your wrist, don’t snap it.” It’s that simple. The wrist action is something like a chef flipping a pancake or a crepe, so when you throw that pitch you actually have to ease up on it vs. what you do with a curveball. I threw my curve with a sharp karate-chop wrist snap, so in familiarizing myself with the slider I had to learn to ease up on it. And what I got with that slider was a sharp late break—it would come in there looking for all the world like a “fast ball” (which, actually, I didn’t have), and then it would suddenly break—not a big break, but very sharp, and it threw the batters’ timing off something fierce. In fact, a lot of pitchers who have been having trouble with the curveball will do very well with that slide piece.
Now, about pitchers who slow down their arm speed when throwing any kind of changeup—didn’t anyone ever tell them that this is one of the cardinal sins in baseball, a no-no if ever there was one? That was another thing my pitching coach told me, way back when—you have to throw all, and I mean all, of your pitches with the same arm motion and the same arm speed if you don’t want to telegraph them. otherwise you might as well yell out to the batter, “Hey buster, here comes a changeup” or “Here comes a—” whatever, thus giving them time to get set for something they can blast over the fence, out of the ballpark and into the kitchen window across the street! YOU JUST DON;T DO THAT. Not if you want to win the game…and if you want to last in the major leagues.
And speaking of changeups—that same pitching coach told me that just about any pitch can be turned into a nice changeup. He demonstrated a few of them for me, and I grabbed a couple of them, worked them up and added them to my snake-jazz repertoire. It all has to do with the different grips one can use, or holding the ball further back in the hand or further forward, or both. But you absolutely have to throw everything, and I do mean everything, with the same motion and the same arm speed—I can’t emphasize this too strongly. And you have to move the ball around—high, low, inside, outside. and stay away from the middle of the plate. By the way, I was one of those infuriating, exasperating sidearmers who used the crossfire extensively—that’s a beautiful and deadly move that works only with the sidearm delivery—and that gave me three times as many pitches, much to the discomfiture of the opposing batters.
Okay, That’s my seventy-five cents’ worth (rampant inflation, you know). I hope this clears up some of the confusion. 8)