CREATE TABLE table_name_73 (round VARCHAR(255), draft VARCHAR(255), pick VARCHAR(255), nationality VARCHAR(255), position VARCHAR(255))
In which round was Position G  from the United States drafted as Pick 13 in 1971-1 1971?
    
SQL: SELECT round FROM table_name_73 WHERE nationality = "united states" AND position = "g" AND pick = "13" AND draft = "1971-1 1971"