What does it mean for a man to tell a fortune?

Men belong to yang and women belong to yin. . .

It is not often said that yin flourishes and yang declines, but that fat people, women are yin and men are yang.

Another example is volleyball in China. The women's volleyball team won the world championship, but the men's volleyball team got nothing (poor). This is what people call "Yin flourishes while Yang declines".