I incorporated a lot of Balyi’s work into one of my Masters papers regarding the training of youth athletes. His model is incredibly sound, and is based on the physiological growth and development of the human body, and how training should be adjusted/focused depending on what phase of growth the body is going through at a given age. His recommendations especially take advantage of ‘optimal periods’ - windows of opportunity where athletic qualities can be most optimally developed during growth and maturation of the young athlete.
The model has gained SOME popularity in Canada (he is a prof at the University of Victoria in British Columbia), but seems to have gained the most acceptance in the UK, and to some extent, Australia. Haven’t heard it mentioned too many times in American publications (aside from the article below, not a big surprise).
The article you cited is probably the most thorough explanation of the model I have seen in any of the literature on the web.
The article in Olympic Coach is also brief but good, and has a good chart at the end that summarizes the model very succinctly:
When I get around to it, I’m going to get the coaching manual I wrote based on the growth and maturation process in young athletes, the LTAD model, and recommendations for the training of the athletes in each stage (based a lot on Bompa’s and Balyi’s work) posted on James Smith’s site. He asked me for it a long time ago, but I haven’;t quite got around to getting it too him. I’m also writing another article that may be posted somewhere in the near future.