Table schema:
CREATE TABLE table_name_50 (to_par VARCHAR, country VARCHAR, place VARCHAR, score VARCHAR)

Question: What is the to par of the player from the United States with a place of t1 and a 76-68=144 score?
SQL: SELECT to_par FROM table_name_50 WHERE country = "united states" AND place = "t1" AND score = 76 - 68 = 144