Dee ihe ga-aga n'ihu na paragraf a - Aitken mụtara chess n'aka nna ya mgbe ọ dị afọ 10. Ọ bụ onye mmeri Scottish na 1935, 1952, 1953, 1955, 1956, 1957, 1958, 1960, 1961 na 1965, nke ikpeazụ ya na PM Jamieson. Ọ bụkwa onye mmeri na London n'afọ 1950. N'afọ 1959, o nwetara nsonaazụ kacha mma ya na British Championship, ebe ọ kwụsịrị n'ọnọdụ nke asaa. Aitken nọchitere anya Scotland n'egwuregwu chess anọ. Ọ na-agba bọọlụ n'asọmpi Stockholm 1937
, na-enweta naanị 32.4% mana o meriri onye Sweden GM Gideon Ståhlberg ma soro onye American GM Samuel Reshevsky mee ihe. Ọ gbara bọọdụ nke abụọ na Munich 1958 na Tel Aviv 1964, na-enweta 67.6% na 28.1%. Aitken gbara bọọdụ nke isii na Skopje 1972, na-enweta 38.9%.