Before explaining why I use a fishing rod, check out the YouTube clip below which shows a man casting a large rod off a pier. See if you can figure out why I use casting a fishing rod as an analogy for better pitching. Hint: don't focus on the fisherman. Focus on the rod.
In order for a pitcher to get the most out of his body to allow it to throw with the most velocity, he has to develop the proper timing and mechanics that mimic the action you just saw in the fishing rod. Let's review how a fisherman casts a rod. He starts by holding the rod horizontally with the bottom of the rod leading forward. Keeping the bottom relatively still, he then very quickly whips everything over the top. The bending of the rod when this whip starts and progresses creates an enormous amount of energy that is eventually transferred up to the tip of the rod as it bends and whips over the top. This energy, of course, is what makes a fishing lure travel a very long way with lots of velocity. Now let's say the fisherman did it a different way. Let's say he started the rod straight up and down (vertical) and moved the top part of the rod forward to cast the lure. What do you think would happen? If he held it vertically and moved the top part of the rod first, the lure would not go very far and certainly would not have developed a lot of velocity. That's because no energy in the rod was created and transferred upward.
Now watch this clip of Clay Buchholz and see if you can recognize the connection with pitching.Which part of his body leads on the way to home plate? The top part (head, shoulder, etc) or the bottom part (his lead foot)? The answer is the bottom part. His lead foot. One big problem that young pitchers have is that they "fall" towards home plate. In other words, they lead towards home plate with their front shoulder, front hip, or sometimes even their head. That's the same as holding the fishing rod vertically and casting by moving the top part of the rod first. No distance or velocity can be generated. Clay Buchholz and virtually every other successful pitcher keeps his weight back and leads towards home plate with the outside of his front foot. With the bottom of his body (the foot) going first, his weight is able to stay back very much like the horizontal fishing rod. When the lead foot lands, he can now very quickly whip everything over the top in order to throw. Just like the fishing rod. Leading with the foot (like leading with the bottom of the rod) allows a great deal of energy to transfer up the body on the whip which eventually creates a great deal of arm speed at the top.There certainly are other parts to the pitching mechanics that help with all this but it all starts with leading with the bottom of the body - the lead foot.