CREATE TABLE table_name_22 (to_par VARCHAR(255), country VARCHAR(255), place VARCHAR(255), score VARCHAR(255))
What is the to par of the player from the United States with a t6 place and a score of 70-73-68-73=284?
    
SQL: SELECT to_par FROM table_name_22 WHERE country = "united states" AND place = "t6" AND score = 70 - 73 - 68 - 73 = 284