Mezue ahịrịokwu na-esonụ: Na World Chess Championship cycles, Portisch gbara na Interzonal ọ bụla site na 1962 ruo 1993, iri na abụọ na mkpokọta. Ọ tozuru oke maka ọkwa ọzọ, asọmpi ndị Candidates, ugboro asatọ: na 1966, 1969, 1975, 1978, 1981, 1984, 1987 na
1990 cycles; na nsonaazụ ya kachasị mma mgbe ọ ruru ọkara ngwụcha ndị Candidates na 1977 na 1980.