CREATE TABLE table_51417 ("Year" FLOAT, "Event" TEXT, "Record" TEXT, "Athlete" TEXT, "Nationality" TEXT)

Which athlete performed before 1984 in an 800 m event?
SELECT "Athlete" FROM table_51417 WHERE "Year" < '1984' AND "Event" = '800 m'
SELECT "Athlete" FROM "table_51417" WHERE "Event" = '800 m' AND "Year" < '1984'