Mezue ahịrịokwu na-esonụ: Gregory John Kosc (amụrụ na Eprel 27, 1949) bụ onye bụbu onye ọka ikpe na Major League Baseball onye rụrụ ọrụ na American League site na 1976 ruo 1999. Ọ na-ekpe ikpe na World Series na 1987 na 1997, na na All-Star Game na 1981 na 1992. Ọ rụkwara ọrụ na American League Championship Series n'afọ 1979, 1988 na
1993, na American League Division Series n'afọ 1996 na 1997. Kosc yi uwe ejiji 18 mgbe ndị American League umpires nakweere ha na 1980.