I’m certainly not going to shred Priceless’s advice, or Coach B’s–at 9 years old, pitcher/thrower training should be kept pretty simple. I liked Priceless’s analogy that “pitching is like throwing with a leg lift” (and with a bit more focus on precisely hitting the target).
Where I often disagree with the “let him do whatever comes naturally” type of notion is that most of us actually do not seem to throw a baseball very efficiently without some training, either from flat-ground or from a mound. There are really very few “pitcher savants” in the entire history of the sport, I think. The few that might qualify as savants, because they had highly public and successful careers, belie the simple fact that they are a very, very tiny fraction of a percent of all baseball pitchers.
As insightful as Priceless’s words are, there is also this to consider (and I hope he might agree with me): At 17 years old, Priceless has undoubtedly seen the entire spectrum of abilities at each successive level leading up to his current level. However, at the level he is currently playing, baseball has effectively already weeded out the pitchers and position players who don’t throw efficiently. The ones who made all the cuts along the way and are still playing alongside of Priceless did not get there on natural ability, for the most part. Baseball is one of, if not the most, skill-dependent sports in existence. Performance of high-skill sports does require training to be good–but at 9 years old the baseball skills-training just needs to be age-appropriate.
Here is one very simple thing that may help your son, if you work with him on it consistently: Your son’s starting posture should be lowered a little with a slight bend in the knees–show him how to start every delivery in a posture that is similar to a “free-throw” posture, and to keep that slightly lower posture as he strides forward to deliver the ball.
Here is another tip: Your son cantilevers backward somewhat as he lifts his leg. (At 9 yo, he won’t know what ‘cantilever’ means, so you can see why you may have to stay deeply involved in his training for awhile. Somebody (you) has to crunch through all the hard information, and misinformation, and make sense of it all…
So, anyway–cantilevering backward during his leg lift is counterproductive. Instead (and you should learn the feel of this yourself, so you can demo it for him)…from his balanced starting posture, your son should get his front hip moving toward the target at the same time that he is lifting his leg. This will get his momentum headed in the right direction (the target!!) and will give his moving parts less time to go out of balance as he completes his delivery.
If he trains for awhile to do those two things,i.e., adopts a lower (more stable) posture and gets his booty going toward the target from commencement of his leg lift, he will develop two things: (1) A noticeable drag-line in the dirt that is made by his post foot and (2) better strike-throwing consistency.
There are many other things that pitchers are always working on and honing and refining. But those two simple things might help your boy, in my opinion.
Again, at 9 yo, he will not be able to understand what he should or shouldn’t be doing on his own…he’s going to need your continued support and help. If you both stick with this, by the time he is a teenager you two may still be enjoying baseball together as one of your strongest bonds.
Here’s a young pee-wee who still needs work but who does a lot of things very well: I don’t intend that your son should copy his mechanics verbatim, but just notice the points made above: He starts in a comfortable balanced posture, he has a drag-line, and his booty starts moving toward the target before the top of his leg-lift. There is no backward cantilevering.