My recently turned 13yo has been using DL's htkc youth for 2 years (I have l also used Alan Jaeger's, Phil Rosengren's, Lantz Wheeler's, TBR's and Brent's 3x program as well). My 10 year old started it this year. Both my kids have above average velocity and would mostly throw with serious intent during the season. I agree with Mike Reinold that WB is not for anyone and I am fully aware of the risks but there is risk with all ballistic throwing over a several month span. I think a WB program should be progressive and have an age appropiate s&c component, this is why I like DL. For me the main benefit of this program for my kids is the arm (and overall) strengthening component to protect the joints.