Original sentence: As a chess trainer, he worked between 1983-1986 as a second of GM Zoltán Ribli, between 1980-1994 as one of the coaches of Zsuzsa Polgár and in 2005, was appointed a FIDE Senior Trainer  (the highest trainer licence of FIDE)
Edited sentence: As a chess trainer, he worked between 1983-1986 as a second of GM Zoltán Ribli, between 1980-1994 as one of the coaches of Zsuzsa Polgár and in 2005, was appointed a FIDE Senior Trainer (the highest trainer licence of FIDE)