Need a better change up and knuckle-curve

[baseball=my life]

I have seen many major leaguers who follow up a good fastball with a change up. Right now, I've probably thrown like 3 good change up. My knuckle-curve has good break but I want a Mike Mussina knuckle curve:)

[EdmondsFan#1]

are you using a circle-change?

Since there is a few or so different ways to grip a change up i would stick with the one that is the most uncomfortable that way you don't throw it as hard.

[baseball=my life]

Well I've tried throwing both actually. I had a little bit more success with the circle change though.

[JLeicester]

The biggest key to throwing a good change-up is to have fastball arm-speed.
Be sure that you are trying to throw the pitch as hard as your fastball and aim for the top of the plate. Let the grip, this will need continually tinkering with, create the lack of speed and movement.
Try playing catch using a change-up grip for an entire day, once or twice a week. this will speed up the learning process and give you a feel for the grip.
-sorry, I can't help you with the Knuckle-curve-