CREATE TABLE table_71891 ("Res." CLOB, "Record" CLOB, "Opponent" CLOB, "Method" CLOB, "Event" CLOB, "Round" FLOAT, "Time" CLOB, "Location" CLOB)

Who was the opponent at GCM D.O.G. 4?
SELECT "Opponent" FROM table_71891 WHERE "Event" = 'gcm – d.o.g. 4'
SELECT "Opponent" FROM "table_71891" WHERE "Event" = 'gcm – d.o.g. 4'