As far as I know the Soviet Union competed seriously from Helsinki' 52. Of course the GDR subsequently excelled in ladies sports with the help of the chemists, Romania in particular excelled at gymnastics using svengali like coaches, Eastern Europeans dominated olympic soccer and Cubans were virtually unbeatable at boxing. Weightlifting was dominated by Stallinist nations also. What If the PRC, the regime and its athletes and massive population and yes it's chemists embraced the olympics before they actually did, say at Helsinki? They would excel at more than just ping pong, of course the cultural revolution would see great champions denonounced!