I am in the process of converting my DD from HE to IR. After reading Java's drive mechanics and Boardmembers stickies we are starting over completely. One question I have is about back swing. My DD has very long arms with very flexible shoulders. The picture below is from this spring when she was still 9. As you see her arm gets completely vertical in her backswing. Intuitively I think it is too much(besides looking painful) but I was wondering what is ideal and why?