All I can say is that im glad im 14 and have no worry of having the 16s start being played with green dot balls. Yes some of the kids back in 10s hit weird shot and moon balls, but the serious players had good coaches that taught them not to care about results and just work on developing there games. Now younger kids are having to learn the game twice. A twelve year old is playing with a different ball and then switching to a regalar ball when they are 13. When Nadal was 13 he was two years from going pro and wasn't worrying about switching to a new ball.