Why is the disc king Duxiu called disc four?

Grade. Wang Duxiu, formerly known as Wang Liang, is a master of the game in "QQ Speeding", and also the anchor of a penguin, because he once said in the live broadcast that he was the fourth and youngest in the family, but at the same time he earned the most money in the family, which made everyone laugh. Later, his fans kept calling him Lao Si.