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, the line of scrimmage of the team without the ball is 1 yard past their side of the ball. The player snapping the ball (known officially as the "snapper" in rule books) delivers the ball to another player, and that action is the snap. The snapper may hand, throw, or even roll the ball to the other player. 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 snapper almost always passes the ball between his legs, but only in Canadian football is that required.
In the standard , the is the snapper and is situated in the middle of the line of scrimmage. Only in is the center required by rule to be the snapper. In other codes, a , tackle, tight end or split end can legally deliver the snap; such scenarios, known as an unbalanced line, are seldom used outside of trick plays and novelties.
Exchange of the snap between the center's legs.
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.
In the (and presumably other levels), the snap is considered a backward pass and not a handoff. This rule was highlighted in a preseason 2014 game between the Arizona Cardinals and the Minnesota Vikings, when Zach Bauman picked up the ball from the turf after a bad snap and ran it six yards for a touchdown. Since the loose ball was a dropped backward pass and not a fumble, any player could pick up the ball and advance the ball—if it were a fumble, only the original carrier could advance the ball.