How to throw a good 12-6 curveball without supinating?


Hi everyone, I read everywhere that supinating the arm is not good because it may cause some serious pain and injury to your arm, elbow etc.

But how can you throw a good 12-6 curve without “doing the karate-chop”? I remember someone saying that doing the karate-chop is supinating your forearm and I’ve been taught that’s how you throw a curveball…

And if you stop and think about it it is quite hard to throw a 12-6 curve pronating your forearm isn’t it?

This is how I do when I pitch a curveball. I do the “karate chop” to release the ball and as soon as I let it go I pronate my forearm.
Is this how you are supposed to throw a curveball?

Is there any more advice about throwing a wicked 12-6 curveball without putting extra pressure on your arm?



I would also like to know this. I have a really hard time getting my curveball to break. It just goes like a fastball when I throw it and I do “karate chop”. So I have recently switched to throwing a knuckle curve which I think is easier to throw.


First, let’s make sure everyone understands what we want to achieve when it comes to curveballs.

A fastball is thrown with backspin, which is why it stays up (and in some cases looks like it rises). The more backspin you can put on the ball, the more it will stay up.

In contrast, a curveball is thrown with topspin. This topspin is what causes the ball the drop (it creates a region of high pressure on the top and front of the ball).

To put topspin on the ball without supinating the forearm, you have to create the spin using the fingers and not the wrist or the forearm. That is why guys with big hands and long fingers tend to throw the best curveballs.

As I understand it, the way Dr. Mike Marshall wants his guys to throw the curveball is by using a motion that is similar to snapping the fingers. The stronger your hands are, the easier this is to do.


Generally speaking you will end up pronating anyways unless you really force the supination. A properly thrown curve puts less stress on the arm than a fastball simply because it isn’t thrown as hard. The problem with younger players throwing the curve is that it is a different stress, not that it is more stress.

I’d recommend sticking with the classic cue of throwing the 12-6 curve around a barrel. To get the big break you throw it a bit slower, but try to stay on top of it as much as possible and to get the sharp break you throw it a bit harder and extend a bit more. It is really not a difficult pitch to master if you work on it and speaking from experience you don’t need large hands or long fingers to do so.


Just make sure that when you throw it you don’t drop your elbow…because if you do then it will stay up in the zone, not break, you’ll get absolutely crushed, etc…so like they said stay on top of it and if you slow your arm speed a bit it will fool the hitter better because of the change of speeds and will also break more or at least should…i hope this helped a little…


There is a difference in supinating during forward acceleration of the arm and simply maintaining the supination during forward accelleration.
Pronation of the arm always occurs after you release the ball regardless of what pitch you throw.

Throwing a curveball properly still puts more stress on the arm than a fastball simply because the arm rotates a further distance to the pronated position after release. When throwing a fastball, the arm rotates 90 degrees from the fastball position to the pronated position. When throwing a curveball, the arm rotates 180 degrees from the supinated curveball position to the same pronated position. When you throw a curveball and supinate during the throw, the arm rotates 90 degrees into the supinated position, reverses directions and then rotates 180 degrees into the pronated position. This changing of directions is really hard on the arm.

I wouldn’t worry too much if you throw 12-6 or 1-7 or 2-8 as a large part of that is arm slot and you should be using your natural arm slot. Kust make sure to set the arm angle (i.e. supination) early when the ball is in the glove so that when forward acceleration is started, the arm is already supinated.