The Thomas Cup competition is an international team tournament for supremacy in men's badminton (its female counterpart is the Uber Cup). Beginning in 1948-1949 it was held every three years until 1982 and thereafter it has been held every two years. Twenty-six national teams, each (except the defending champion nation) starting from one of four qualifying zones (Asia, Australasia, Europe, and Pan America), vied for the Thomas Cup during the 1963-1964 badminton season. Qualifying zone winners played-off in Tokyo, Japan for the right to face defending champion Indonesia, which was exempt from earlier "ties" (team matches), in a conclusive challenge round tie. Prior to 1964 the defending champion nation had regularly hosted both the inter-zone playoffs and the challenge round, but a rules change effective that year prevented the same defending champion nation from having this advantage for two successive Thomas Cup seasons. For a more detailed description of the Thomas Cup format see Wikipedia's general article on the Thomas Cup.