The preliminaries are the schedules arranged by the football associations of all continents, but the number of participants in the World Cup varies from continent to continent. Take the 20 10 World Cup as an example. There are 3 places in Europe, 5 places in Africa, 4.5 places in Asia, 0.5 places in Oceania, 3.5 places in North America and 4.5 places in South America.
Generally speaking, the qualifiers will end before the end of the year before the World Cup, that is, the 20 10 World Cup qualifiers will end before the end of 2009, because the World Cup was drawn in February 2009.