CREATE TABLE table_203_378 (id DECIMAL, "against" TEXT, "played" DECIMAL, "won" DECIMAL, "drawn" DECIMAL, "lost" DECIMAL, "win %" TEXT)

which country have they played against the most ?
SELECT "against" FROM table_203_378 ORDER BY "played" DESC LIMIT 1
SELECT "against" FROM "table_203_378" ORDER BY "played" DESC NULLS LAST LIMIT 1