I will have to agree with iTT. For all out purpose, yeah, Xu Xin's RPB isn't nearly as good as Wang Hao. However, for his game, it is absolutely perfect. It's designed to just be almost a reactionary shot. He hits it right after the bounce mostly, so it gives other players very little reaction time. It's not supposed to be flashy or amazing, it just is supposed to serve its very specific purpose, which is to give opponents so little reaction time, that all they can do is hit it back, which then gives Xu Xin time to walk around to his forehand. When someone has such an insanely good forehand as Xu Xin does, to use and rely on his backhand more, like Wang Hao would actually be a detriment for him right now. Maybe when he gets older he can put more time into developing it, but at the moment his rpb is what it needs to be. If you watch his games, even against Boll, his rpb isn't really a weakness at all. He actually wins more points either from it, or from what it sets up than many people give it credit for.