These pro golfers are that good...they know the trajectory of all their clubs.
Bobby Jones was an incredible golfer back in the 20s and 30s. He has some old black and white instruction lessons on video that he filmed. They are so good they are still aired today and have valuable insight into the golf swing.
Anyways on one of these lesson tapes they set up a camera about 150 yards in front of Bobby. Off of the fairway with a low iron he starts hitting balls at the camera. You see one go just left of the camera, one go just right of the camera, and the third hits the lens dead on. He had that accuracy with the inferior balls and equipment of 70 years ago a half decent pro today knows what he is doing.