The sport is called Jianzi (毽子). Most often seen being played by old folk in Chinese parks and public spaces, in its recreational form, it is a game of improbable behind-the-back shots and strange flicks that you are sure must be easier than they look if a bunch of sixty-year olds can pull them off so effortlessly. It is also, believe it or not, the national sport of Vietnam.
I spotted these guys playing in the square near Cheung Chau Praya on Saturday. Every time I took my phone out to film them, the shuttlecock would be on the floor within about four seconds. When I put it away, they turned into freestyling world-beaters again. So it goes. Still, there were some killer moves on display. Check out the clip.