The cricket world cup puts the world's best cricketing nations against one other. It is played in the 50-over format of cricket. There are competitions for both men and women. It first appeared in 1975. 2. Every two years, the ICC T20 World Cup conducts a T20 world cup (generally). The event is held under its own banner rather than that of the other major cricket tournaments - the Test match series known as the Cricket World Cup, and the five-day game called the World Series Cricket. In addition to the men's and women's events, there is a youth version called the ICC Under-19 Cricket World Cup. This takes place every year and is only for players who are under 19 when the tournament starts. Finally, there is a team of retired cricketers called the ICC Cricket World Cup Committee which selects the countries that will compete in each edition of the tournament. Each nation enters a team of 15 players in the men's competition and 13 players in the women's tournament. They can choose their squad within these limits, but once they enter the arena of play during the World Cup, they cannot change their lineup from day one until the end of the last match. A player has to be present at three of the four matches to remain in the tournament. If he fails to do so, then his country will be eliminated. In addition to national teams, international teams also take part in the World Cup.