Every year when I went to my hometown for Xmas I set up a match play session with one kid who I had worked with a little bit back when I taught tennis. When he was 9, we was one of the top players in the nation. Every year he has improved immensely. When he was 14 he took a set off of me. He had very little power in his game, in fact he was starting to fall behind some of the other top juniors in the country because of his size. His consistency, placement, and timing were flawless. After the first set my legs were ready to quit. He could routinely angle his forehand so far off the court that I was constantly hitting shots from outside the doubles alley. It was pretty amazing. I'm a fairly strong 5.0 player, but all the pace I have in my game he was able to use against me because he timed his shots so well it stole all my pace. There is no way his serves were above 100mph, while mine easily break 100mph, but that didn't phase him at all.
Unfortunately I haven't been back the last two years, but I'm pretty sure now I wouldn't stand a chance now.