This tutorial is geared for teaching kids with little or no pitching experience. It can also be used to tweak the deliveries of those kids who need a little work. Everything explained here is done so for a right handed pitcher so if your pitcher is a lefty, just change the rights to lefts and vice versa.
Stretch vs. wind-up – Hands down I only teach the stretch to new pitchers. For both wind-up and stretch the pitcher is trying to get to the same set position so they can deliver the ball to the plate (accurately). I advocate eliminating all the extraneous motions and simplifying the delivery.
Toe the rubber – In order for kids to use their entire body when throwing (instead of all arm) they should stand with a closed stance. What that means is that their left foot should be 3-4" closer to third than their right. This will help them stay closed when they start their leg kick giving the pitch more power.
Leg kick – With the above mentioned closed stance, the left knee is brought to the body's midline, about belt high. The knee comes to the midline to help turn the body slightly away from the hitter/catcher. We call this "showing the hitter your number". If we don't close slightly it's easy for the pitcher to open too early causing them to throw all arm. (1st picture)
Glove/ball position – The glove should be kept in front about 4" from the center of the chest. This should keep both elbows at about a 30° angle. The pitcher should try and maintain this 30° angle until the pitch is released. When the knee gets to the top of the leg kick, the first motion to the plate will be the left elbow. It will actually pull the upper body toward the target and then pull down to the outside of the left leg. This will get the upper body involved in the pitch and eventually the follow through. (2nd & 3rd picture)
The pitch – It is my opinion that a pitcher cannot take the ball out of the glove too early. As the elbow starts toward home have the pitcher go ahead and get the ball out of their glove. This will help their timing and the earlier the ball leaves the glove, the lower the pitch will go. (The longer it stays in, the higher the pitch.) The ball should leave the glove and make a low arc till the arm is almost fully extended. Once there, unleash. Below is a great example of what I'm trying to convey.