Elitserien is the highest level of professional baseball in Sweden and is operated by the Swedish Baseball and Softball Federation. The number of teams in Elitserien has varied through the years. The Swedish baseball championship was inaugurated in 1956. Teams compete in the regular season for a chance to make the playoffs and battle for the Elitserien Cup Championship. Teams also play many exhibition games and events within Sweden, and throughout Northern Europe, in an attempt to help the sport gain popularity. Each organization has an Elitserien team, as well as minor league and youth league teams. Starting in 2017, at the end of the playoffs, a championship series is played between the best Swedish team and a team of imports from other countries.