nfl score

A safety or safety touch is a type of score in American football and Canadian football and is worth two points (with one very rare exception). In American football, it is the only means by which a team not in possession of the football can score points. A safety may occur in a variety of ways, most commonly when an opponent in possession of the football is tackled in his own end zone.
Among the ways the defensive (non-possessing) team may score a safety are:
an opponent in possession of the ball is tackled in his own end zone, an opponent in possession of the ball steps out of play (i.e., across the side line or end line) from his own end zone, an opponent snaps, laterals, or fumbles the ball out of play in his own end zone, an opponent downs (kneels or falls on) the ball in his own end zone (an intentional safety), the opposing team has a punt or kick blocked, and the ball then goes out of play in their own end zone, the opposing team commits certain penalties, such as holding or intentional grounding, in their own end zone. Not all of these scenarios result automatically in a safety. If a player on the defense gains possession of the ball in their own end zone through a fumble recovery or interception and is tackled there, it is a touchback, not a safety. If he makes an interception outside of the end zone, his momentum carries him into the end zone and he is tackled there, his team gets the ball at the spot of the interception. However, if a player gains possession of the ball and retreats on his own initiative into his end zone where he is tackled, it is a safety for the opposing team. Similar rules apply on punts and kickoffs.
An official signals a safety by holding his hands above his head, palms touching.
Safeties are the least common of scores in American football, due to the relative rarity of the circumstances that could produce a safety. No National Football League team has ever recorded more than four in one season. Safeties usually occur when the offense starts a play close to its own end zone. In such cases, offenses tend to run very conservative, low-risk plays to avoid a safety.
Intentional safeties are rare, but not unheard of, particularly in Canadian football. For a discussion of this strategy, see the "Elective safeties" After a safety, the team that gave up the points kicks off to the other team from its own 20-yard line (in American football) or 35-yard line (in Canadian football.) This is termed a free kick: the kicking team has the option of employing a punt, a drop kick, or a place kick from a teammate's hold. Unlike the kickoff, a kicking tee may not be used. A punt is the most commonly chosen option, whereas a drop kick is virtually unheard-of in modern football.