Baseball has often been a demonstration sport at the Olympics, having been demonstrated in 1912, 1936, 1956, 1964, 1984, and 1988. Invented by Lauri Pihkala, pesäpallo is a baseball variant that is mostly popular in Finland, although it is also played a little bit in Germany, Sweden, Switzerland, Australia, and Northern Ontario. The game is also considered similar to brännboll, rounders, and lapta. A single game was played as a demonstration in 1952, held in the main Olympic Stadium, between two Finnish teams representing the Finnish Baseball League and the Workers’ Athletic Federation. Pesäpallo has only been an Olympic demonstration sport in 1952. A World Cup is held in the sport every three years, since 1994, but usually with only 3-5 nations competing.