CREATE TABLE table_203_257 (id DECIMAL, "week" DECIMAL, "date" TEXT, "opponent" TEXT, "result" TEXT, "attendance" DECIMAL)

what team played the last game of the 1981 season ?
SELECT "opponent" FROM table_203_257 ORDER BY "date" DESC LIMIT 1
SELECT "opponent" FROM "table_203_257" ORDER BY "date" DESC NULLS LAST LIMIT 1