CREATE TABLE table_13147 ("Player" TEXT, "Country" TEXT, "Year ( s )  won" TEXT, "Total" FLOAT, "To par" TEXT, "Finish" TEXT)

which To par has a Country of united states, and a Player of dave stockton?
SELECT "To par" FROM table_13147 WHERE "Country" = 'united states' AND "Player" = 'dave stockton'
SELECT "To par" FROM "table_13147" WHERE "Country" = 'united states' AND "Player" = 'dave stockton'