The IIHF U18 World Championship is an annual event organized by the International Ice Hockey Federation for national under-18 ice hockey teams from around the world. The tournament is usually played in April and is organized according to a system similar to Ice Hockey World Championships and World Junior Ice Hockey Championships. The United States has dominated the tournament with nine championships followed by Finland, Canada and Russia with three. Countries generally send their best team to this tournament, however, several top North American and European amateurs may not participate as in April both the United States Hockey League (USHL) and Canadian Hockey League (CHL) are still involved in league playoffs. Players who do not participate in the World Championship due to their respective league postseasons have the alternative of representing their country in the Ivan Hlinka Memorial Tournament in August.