CREATE TABLE table_203_383 (id DECIMAL, "week" DECIMAL, "date" TEXT, "opponent" TEXT, "time" TEXT, "game site" TEXT, "tv" TEXT, "result/score" TEXT, "record" TEXT, "bye" TEXT)

which opponent was the last opponent to play at the soldier field ?
SELECT "opponent" FROM table_203_383 WHERE "game site" = 'soldier field' ORDER BY "date" DESC LIMIT 1
SELECT "opponent" FROM "table_203_383" WHERE "game site" = 'soldier field' ORDER BY "date" DESC NULLS LAST LIMIT 1