CREATE TABLE table_203_455 (id DECIMAL, "round" DECIMAL, "#" DECIMAL, "player" TEXT, "nationality" TEXT, "college/junior/club team  ( league ) " TEXT)

which nationality has the least players ?
SELECT "nationality" FROM table_203_455 GROUP BY "nationality" ORDER BY COUNT("player") LIMIT 1
SELECT "nationality" FROM "table_203_455" GROUP BY "nationality" ORDER BY COUNT("player") NULLS FIRST LIMIT 1