I love your kid’s delivery…he looks like Brad Ziegler (Oakland A’s right-handed set-up man) or a right-handed version of Javier Lopez (SF Giants left-handed set-up man).
Unfortunately, though, unless you are blessed to live in an area with fewer know-it-all kids, parents, and coaches than usual, your son and you are probably going to hear a lot of bad advice about his arm-slot: Gotta get over the top, gotta get the arm up, side-arm pitching will hurt his arm, blah, blah, blah…this is just ignorant chatter and if you can ignore it and help your son develop and optimize his mechanics over the next few years without messing with his arm-slot, he might turn into something pretty special.
In fact, Walter Johnson was one of the most resilient pitchers in baseball (more than 400 wins over a 21 year career with an MLB club that was often terrible) and he was also a side-armer with a seemingly effortless delivery…
Here’s the deal: Hitters at all levels are trained from their earliest experience at the plate to look for the pitcher’s release point and then track the ball as far as possible. On average, hitters develop their skills while looking for the ball to come out of a pitcher’s hand from a 3/4 or high-3/4 slot these days—don’t underestimate the power of this consistent training of young hitters. Very few hitters–especially same-side hitters (righty hitters for your son) know how to hit against a decent side-arm delivery.
First, the ball is hard to pick up because reflex action tends to make the hitter look for a 3/4 release, even after he knows rationally that your son is not throwing 3/4.
Second, that side-release will make the ball look like it’s behind the hitter’s rear-end at release–a very unsettling feeling for most hitters.
Third, because the spin axis of a side-arm fastball is 90 degrees different from that of an over-the-top delivery and maybe 45 - 60 degrees different from the spin axis of a fastball from the 3/4 slot…it’s going to have a pattern of movement that is unexpected to most hitters.
Your question about the circle-change: Yes, it is hard for a side-armer to use that pitch. Most youngsters can’t grip or throw a really good one anyway but a side-armer may have the feeling that the ball is going to drop out of his hand before it is released from a proper circle-change grip.
My son is also a side-armer and he uses these three pitches: (1) A sinking fastball (2) a slider (it is physically very difficult for side-armers to throw a true curveball) and (3) a split-finger fastball as his changeup.
If you want to discuss more about any of this with me, shoot me a PM…