The four major professional sports leagues in North America are NBA (National Basketball Association), NFL (National Football League), MLB (Major League Baseball, Major League Baseball), NBA (National Basketball Association) and NHL (National Hockey League). Except basketball, the other three sports are a little strange to us, because we rarely have contact opportunities in China. But in fact, in the ranking of popular ball games in the United States, the number one is not basketball, but football. Baseball, as the national game of the United States, ranks second, and basketball is the third place.