Mezue ahịrịokwu na-esonụ: N'afọ 1992, o meriri n'asọmpi egwuregwu Chess nke mba Sweden. Karlsson meriri ọlaọcha na asọmpi mba ugboro abụọ (1979, 1986) na ọla nchara otu ugboro (1976). N'afọ 1982 na Las Palmas, o sonyere na
World Chess Championship Interzonal Tournament ma nọrọ n'ọkwa nke iri na otu.