In gridiron football, a shift refers to the movement of an offensive player prior to the snap.
There is a distinction drawn between a shift and motion in football. Motion occurs when a player is moving at the time of the snap. A shift occurs when one or more players changes their position on the offensive side of the ball before the snap, causing a change in formation. For example, players may line up initially in an I-formation and then shift the two running backs into wide receiver positions to put the offense in a spread formation. A team may shift any number of players into new positions, so long as they all come to a complete stop for a full second before the ball is snapped to start the play.
The National Football League defines all motion and shift penalties as "illegal motion",while both the NCAA and NFHSAA make a distinction between an "illegal shift" and "illegal motion"; an illegal shift refers to players shifting and not coming to a complete stop before the snap, while illegal motion refers to a player who is in motion towards the line of scrimmage, or a player who is not a "back" in motion. In both leagues, however, the penalty for illegal motion/illegal shift is five yards from the previous spot and replay the down.
Additionally, the offensive team may be charged with the penalty of a "false start" if a player on the offense jumps or moves abruptly, simulating the start of the play. This movement is not normally considered a subset of the "motion" or "shift" rules, as the player is not judged to be moving into a new pre-snap position; they are merely starting the play too soon. This is also a five yard penalty.
Both motions and shift were introduced by Amos Alonzo Stagg.The history of college football involves three notable, distinct shifts:
Canadian football is a sport played in Canada in which two teams of 12 players each compete for territorial control of a field of play 110 yards (101 m) long and 65 yards (59 m) wide attempting to advance a pointed oval-shaped ball into the opposing team's scoring area.
In gridiron football, not all players on offense are entitled to receive a forward pass. Only an eligible pass receiver may legally catch a forward pass, and only an eligible receiver may advance beyond the neutral zone if a forward pass crosses into the neutral zone. If the pass is received by a non-eligible receiver, it is "illegal touching". If an ineligible receiver is beyond the neutral zone when a forward pass crossing the neutral zone is thrown, a foul of "ineligible receiver downfield" is called. Each league has slightly different rules regarding who is considered an eligible receiver.
A snap is the backwards passing of the ball in gridiron football at the start of play from scrimmage.
In gridiron football, a line of scrimmage is an imaginary transverse line beyond which a team cannot cross until the next play has begun. Its location is based on the spot where the ball is placed after the end of the most recent play and following the assessment of any penalty yards.
A wide receiver (WR), also referred to as a wideout, formerly a split end, is an eligible receiver in gridiron football. A key skill position of the offense, it gets its name from the player being split out "wide", farthest away from the rest of the offensive formation.
Gridiron football, also known as North American football or, in North America, simply football, is a family of football team sports primarily played in the United States and Canada. American football, which uses 11-player teams, is the form played in the United States and the best known form of gridiron football worldwide, while Canadian football, featuring 12-player teams, predominates in Canada. Other derivative varieties include indoor football and Arena football, football for smaller teams, and informal games such as touch and flag football. Football is played at professional, collegiate, high school, semi-professional, and amateur levels.
American and Canadian football are gridiron codes of football that are very similar; both have their origins in rugby football, but some key differences exist.
Gameplay in American football consists of a series of downs, individual plays of short duration, outside of which the ball is dead or not in play. These can be plays from scrimmage – passes, runs, punts, or field goal attempts – or free kicks such as kickoffs and fair catch kicks. Substitutions can be made between downs, which allows for a great deal of specialization as coaches choose the players best suited for each particular situation. During a play, each team should have no more than 11 players on the field, and each of them has specific tasks assigned for that specific play.
In gridiron football, clock management is the manipulation of a game clock and play clock to achieve a desired result, typically near the end of a match. It is analogous to "running out the clock" seen in many sports, and the act of trying to hasten the game's end is often referred to by this term. Clock management strategies are a significant part of American football, where an elaborate set of rules dictates when the game clock stops between downs, and when it continues to run.
A formation in football refers to the position players line up in before the start of a down. There are both offensive and defensive formations and there are many formations in both categories. Sometimes, formations are referred to as packages.
Center (C) is a position in gridiron football. The center is the innermost lineman of the offensive line on a football team's offense. The center is also the player who passes the ball between his legs to the quarterback at the start of each play.
Slotback, sometimes referred to as an A-back or "slot receiver", is a position in gridiron football. The "slot" is the area between the last offensive lineman on either side of the center and the wide receiver on that side. A player who lines up between those two players and behind the line of scrimmage fills that "slot". The slotback position is a fixture of Canadian football and indoor football where they act as extra receivers. It is also used in American football where the position requires a versatile player, who must combine the receiving skills of a wide receiver, the ball-carrying skills of a running back, and the blocking skills of a tight end.
In gridiron football, motion refers to the movement of an offensive player at the time of the snap.
The following terms are used in American football, both conventional and indoor. Some of these terms are also in use in Canadian football; for a list of terms unique to that code, see Glossary of Canadian football.
Wildcat formation describes a formation for the offense in football in which the ball is snapped not to the quarterback but directly to a player of another position lined up at the quarterback position. The Wildcat features an unbalanced offensive line and looks to the defense like a sweep behind zone blocking. A player moves across the formation prior to the snap. However, once this player crosses the position of the running back who will receive the snap, the play develops unlike the sweep.
In gridiron football, a penalty is a sanction called against a team for a violation of the rules, called a foul. Officials initially signal penalties by tossing a bright yellow or orange colored penalty flag onto the field toward or at the spot of a foul.
Offside is a minor foul in gridiron football caused when a defender crosses the line of scrimmage ahead of the snap of the ball. The penalty associated with the infraction is the advancing of the ball five yards and a replay of the down.
In gridiron football, an ineligible receiver downfield, or an ineligible man downfield, is a penalty called against the offensive team when a forward pass is thrown while a player who is ineligible to receive a pass is beyond the line of scrimmage without blocking an opponent at the time of the pass. A player is determined ineligible based on his position at the time of the snap. When the ball is snapped, the offense is required to have no more than eleven players on the field, out of whom only six are eligible. On most plays, the eligible receivers include the quarterback, running backs, fullbacks, tight ends, and wide receivers, while the ineligible receivers are offensive linemen, including the center, offensive guards, and offensive tackles.