Oh, try getting a black lab or a collie. They're all OCD, so, once you've taught them how to retreive a ball, every meter you can throw it equals an extra second's peace. Believe me, I can pitch with the best of them. Having a black lab also taught me to carry something close to my own weight, run, roll, jump, jog, and watch where I put my feet; all of this happened by force of circumstances that start with 'ridiculous' and end with 'weird'. These animals are psychotic. It's like they're MDMA-crazed ravers. You know that song that goes 'can't stop raving'? There's a black lab in a nutshell. They're not stupid, it's just they're so dizzy with their own hormones to think most of the time. If you can get them to sit still, they can be incredibly intelligent, but 'if' is the key word. Sometimes you have yell at them and smack them a little bit to bring their oxytocin levels down enough to teach them anything, which you'll find happens a lot more when you're having a good time with them than when you're doing anything serious. To tell you the truth, I think they'd work well as a therapy, the walking headaches.
Anyway, the way that you throw is, as your arm arcs, allow the ball to roll toward the tips of your fingers, and, at a key time, you allow your fingers to act as a springboard to send the ball flying. It doesn't work just to know it: practice. You know you're getting close to having it right if the ball is rolling off the tips of your fingers as you try to make the release, and all you need at that point is a little fine-tuning. You have to learn at that point to keep the tips a little bent, which requires extensive and time-consuming fine-motor training. What I've found works is to sandwich the middle-finger between your first and third finger in such a way as to keep it bent in a slight arc, but it's too stiff to leave any spring if you're doing it consciously. As you make your release, your fingers should spread apart, which is, again, unnecessary to do consciously because it should happen as a result of the mechanics of your hand combined with fine motor training that is developed rather than learned.
For shorter, more accuracy-minded throws, you use the movement of your wrist to make it roll up on the backswing, rather than in the throwing arc. There's an important distinction between a pitch and a throw. In a throw, you don't have a full arc and use mainly your wrist in an undramatic movement.