Claim: Joao de Souza Mendes was a seven-time Brazilian chess champion, playing in the Brazilian Chess Championship 29 times, and playing twice for the Chess Olympiads, a biennial chess tournament which attempted to become part of the Olympic games in 1924, but failed.
Evidence: João de Souza Mendes Júnior (23 June 1892 – 10 July 1969) was a seven-time Brazilian chess champion. Born in the Azores, Portugal, Souza Mendes played in the Brazilian Chess Championship 29 times, winning in 1925 (the first year the tournament was held), 1928, 1929, 1930, 1943, 1954, and 1958. He played for Brazil in Chess Olympiads at Buenos Aires 1939 and Helsinki 1952. The Chess Olympiad is a biennial chess tournament in which teams representing nations of the world compete. For the 1924 Olympics an attempt was made to include chess in the Olympic Games but this failed because of problems with distinguishing between amateur and professional players.