Safety (S), historically known as a safetyman, is a position in gridiron football on the defense. The safeties are defensive backs who line up ten to fifteen yards from the line of scrimmage. There are two variations of the position: the free safety (FS) and the strong safety (SS). Their duties depend on the defensive scheme. The defensive responsibilities of the safety and cornerback usually involve pass coverage towards the middle and sidelines of the field. While American (11-player) formations generally use two safeties, Canadian (12-player) formations generally have one safety and two defensive halfbacks, a position not used in the American game.