CREATE TABLE table_name_68 (player VARCHAR2, nationality VARCHAR2, position VARCHAR2, round VARCHAR2)

Which player from the United States plays defence and was chosen before round 5?
SELECT player FROM table_name_68 WHERE position = "defence" AND round < 5 AND nationality = "united states"
SELECT "player" FROM "table_name_68" WHERE "defence" = "position" AND "nationality" = "united states" AND "round" < 5