So, looking closer at the numbers I have for spin rate and break, I'm not necessarily seeing what I expect to see. Here will be the numbers for particular pitches for a few pitchers. Note I've chosen two top pitchers who throw harder than my son and a couple who throw about the same. Also note these numbers come from Rapsodo and I've noticed, for the most part that recorded velocities seem to be 3-4 mph below what I know they throw. I'm not sure if Rapsodo uses some sort of avg. over a distance, but the numbers seem too low for peak out-of-hand velocity and too high for across the plate:
velocity spin rate horizontal/vertical break
Dalton (my 2018) 87.8 1872 -10.3/11.7 89.0 1783 -10.4/13.3
Zach Argo 87.6 2046 -1.3/20.3 89.0 1978 -3.6/18.4
Ethan Hankins 94.3 2422 -9.1/16.1 93.0 2375 -8.9/16.0
Mason Pelio 87.0 1941 -4.2/16.4 86.6 1926 -9.1/13.9
The first break number is horizontal (left to right) and the second is vertical (measured drop compared to flight path without gravity). I would expect my son't low spin rate to cause a greater vertical break than average. However, this doesn't seem to be true. In fact, he seems to have less sink on his fast ball than most. Instead, what I do see is greater horizontal break, in to right handed hitters, than the other pitchers I look at. Any insight?