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 tended to dominate the World Championships. Most countries send their best team to this tournament, however, Canada may not send its best players as in April some CHL junior teams are still involved in junior playoffs. Instead Canada's top U18 players involved in junior or university playoffs in North America play in the Ivan Hlinka Memorial Tournament in August.