From Love-shy.com wiki: A wiki for the dating-challenged
The "Yao Ming" argument
Yao Ming is used by analogy on the Love-shy.com forums to describe an outlier that does not represent the norm. Using the example of Yao Ming to prove that most Asians are very tall would be incorrect, as he is not only taller than most Asians, but most whites, and every single other player in the NBA. The average male height in Yao Ming's native China is 5'7" (1.7 m), nearly a full two feet (0.6 m) shorter than he is.
By analogy, using an example of an extremely fat man with an attractive girlfriend to prove that any extremely fat man can have an attractive girlfriend a fallacy. It is an example of drawing incorrect conclusions about a broader population from an outstanding sample.
The Yao Ming argument has historically been used by looksists to argue against anecdotal or celebrity evidence that goes against their theories. It is also occasionally used by other schools of thought as an argument tool.