Being one player short used to be the biggest hurdle preventing Liu Xiurong from playing mahjong.

"You cannot do anything but wait for a fourth player or persuade a passer-by to come into the game," said the retired woman in her 50s.

Liu retired several years ago and with her only son studying in East China's Fujian province, mahjong has been one of the few entertainments to distract her from loneliness.