A snap (colloquially called a "hike", "snapback", or "pass from center") starts each American football and Canadian football play from scrimmage.
The ball begins on the ground with its long axis parallel to the sidelines of the field, its ends marking each team's line of scrimmage in American football; in Canadian football line of scrimmage of the team without the ball is 1 yard their side of the ball. The snap must be a quick and continuous movement of the ball by one or both hands of the snapper, and the ball must leave the snapper's hands. The various rules codes have additional requirements, all of which have the effect of requiring the ball to go backwards to a player behind the line of scrimmage (i.e. in the "backfield"). The ball may be handed, thrown, or even rolled, and its trajectory and the ball during that passage are called "the snap". The snapper is almost always the center. The ball is almost always sent between the snapper's legs, but only in Canadian football is that required. Additional rules apply regarding the positioning and stance of the snapper as one of several "line" players in anticipation of the snap.
For a handed snap, the snapper will usually have his head up, facing opponents. For a thrown snap, especially in formations wherein the ball may be snapped to players in different positions, the snapper will commonly bend over looking between his legs. Because of the vulnerability of a player in such a position, the National Collegiate Athletic Association (NCAA) and the National Federation of State High School Associations ("Fed") have adopted rules providing that if a player is positioned at least 7 yards behind the neutral zone to receive a snap, opponents are not to deliberately contact the snapper until one second after the snap (NCAA), or until the snapper has a chance to react (Fed). However, in professional football it is common for a center to be able to practice a single "shotgun" formation thrown snap enough to keep his head up and toss it blindly.
The team entitled to snap the ball will usually know in advance the moment when the snap is to occur as one of their players calls out signals, which usually include a loud sound such as "hut" voiced one or more times, the number of which they know; they are thus said to know the "snap count". Therefore they have a considerable advantage over their opponents. The snapper is not, however, allowed to make motions simulating part of the snap action; therefore their opponents can be confident the first motion of the ball or the snapper's hands is the beginning of the snap.
The snap count is decided on in the huddle, usually expressed as "...on <number>." being the final words spoken by the quarterback after calling the play but before the huddle breaks and the players go to the line of scrimmage. The snap count allows offensive players to have a small head start. The opposing linebacker wants to predict the snap, and build up speed such that he crosses the line of scrimmage exactly as the play begins, so as to increase his chances of getting a tackle for a loss, or a sack. By varying the snap count, a quarterback forces the defensive players to react to the movement of the offensive players, or risk being called for an offsides or encroachment penalty. Unfortunately for the offense, this advantage can sometimes become a disadvantage. When faced by an exceptionally loud stadium, players may be unable to hear the snap count, and are forced to concentrate more on visual cues (silent snap count or a hard count), or risk false start penalties.
Full article ▸