CREATE TABLE table_204_791 (id NUMBER, "event" CLOB, "winner" CLOB, "second" CLOB, "third" CLOB, "fourth" CLOB)

in what two races did chelsea williams earn the same rank ?
SELECT "event" FROM table_204_791 WHERE "winner" = 'chelsea wlliams'
SELECT "event" FROM "table_204_791" WHERE "winner" = 'chelsea wlliams'