Forget the slider. It is one of the toughest pitches on the elbow.
The curve is difficult to teach via the internet.
Some info on c/u's:
The modified circle change is similar to a true circle change, but instead of curling the forefinger all the way back into the web of the thumb, the tip of the forefinger is left touching the tip of the thumb. From the side it would look like the "ok" sign. Curling the forefinger all the way in creates undue stress in the tendons. The ball is held in the last three fingers of the hand, again with the forefinger and thumb on the side. Most pitching books will have a picture of the grip.
Here is a link to a picture of the modified circle:
Modified circleIf that link doesn't work, try:
Second Some get a great deal of movement by using various grips (two seam orientation, four seam orientation, two seam orientation but off center, etc.) with the modified circle. Hand size is not the determining factor in gaining control of the modified circle. Some of my kids with smaller hands mastered this pitch well before kids with big hands.
The three finger change is a three finger grip with the thumb and little finger moved around to the side of the ball instead of being together at the bottom. The ball is still held more in the fingers rather than being pushed back into the palm like a palm ball.
The following illustration is only partially correct. The three fingers on top of the ball are correct. But the thumb & little finger should not be touching together. They should be more around the side of the ball, not directly under.
Three finger, partially correct Some get more movement from the three finger. It can be throw from a two or four seam orienation.
Try both changeup grips for a while (e.g., a month or more). You will probably get one down before the other, maybe a long time before the other.
Throw your c/u when you warm your arm up before practice or games. This will give you a lot more reps, which will mean more control.
Do a little long toss with your c/u grip. This will help you train your body not to slow down your arm when you throw the c/u.
Remember, the c/u is thrown exactly like your fastball. Do NOT slow down your arm, drag your foot, change your stride, etc. The c/u is most deceptive, & therefore effective, when it is thrown exactly like the fastball. Plus there will be better control, since you use the same mechanics for your fastballs & c/u's.
You only need to take about 10-12 mph off your fastball. And just changing the grip alone will accomplish that.
Throw it a lot in practice, warmups, etc. Gain the confidence to throw the c/u on a full count. I have seen my pitchers throw the c/u on full counts, 3-1 counts, etc. And they were successful in doing so. They could throw it well & the batter never dreamed it was coming, so they swung right over it.
"The only time I really try for a strikeout is when I'm in a jam. If the bases are loaded with none out, for example, then I'll go for a strikeout. But most of the time I try to throw to spots. I try to get them to pop up or ground out. On a strikeout I might have to throw five or six pitches, sometimes more if there are foul-offs. That tires me. So I just try to get outs. That's what counts - outs. You win with outs, not strikeouts." – Sandy Koufax
“My job isn't to strike guys out, it’s to get them out, sometimes by striking them out."
– Tom Seaver
“The pitcher has to find out if the hitter is timid. And if the hitter is timid, he has to remind the hitter he's timid.” – Don Drysdale
"Hitting is timing. Pitching is upsetting timing." - Warren Spahn