The National Games officially open in Guangzhou on Sunday, but Hong Kong is already well into its role as co-host and a pivotal centre for the action and organisation over the next two weeks. Tens of thousands of athletes, officials and tourists are expected to descend on the city, which is hosting eight events and there were sell-out crowds at the beach volleyball and men’s handball on Saturday. And while there are tickets still available for sports such as the rugby sevens and triathlon, day...