Mezue ahịrịokwu na-esonụ: N'afọ 1986, asọmpi ndị Candidates laghachiri n'ụdị round-robin ma site na 1991 e mere ọzọ naanị otu Interzonal, mana yana ọnụ ọgụgụ dị elu nke ndị sonyere na iji usoro Switzerland. Ihe
usoro mmeri ikpeazụ eji usoro a (site na 1995 <unk> 1999) gbara ọtụtụ esemokwu gburugburu ma soro ụfọdụ mgbanwe dị ukwuu na usoro ahụ.