question: How many years had a location at Forest Hills and a score of 6–3, 6–3 for John McEnroe?
answer: SELECT COUNT(year) FROM table_name_42 WHERE location = "forest hills" AND runner_up = "john mcenroe" AND score = "6–3, 6–3"
context: CREATE TABLE table_name_42 (year VARCHAR, score VARCHAR, location VARCHAR, runner_up VARCHAR)