the true path is the path of the sweetspot through the impact interval - between impact and seperation. because this impact interval is so short, even though the sweetspot is moving on an arc troughout the swing, the true path is all but a straight line. brian has described it as a straighter line than you can draw free hand.
assuming a straight plane line (a plane line that is parallel to the target line) the true path of the club is only straight toward the target is at low point. therefore if you strike the ball before low point, then with a straight plane line, the true path will be inside out.
hope this helps
