Odds – the likelihood of a team winning, determines the amount of money returned on a bet; see “Oddsmaker”

Oddsmaker – the person in charge of determining a team’s chances of winning 

Offending Team – An offending team is the team that is called for committing a penalty. A penalty (or alternatively a foul) is a sanction that is called against a team when one or more of its players commit a violation of the rules. The majority of penalties result in moving the ball towards the offending team’s end zone. Dependent upon the foul committed, the penalty may be 5, 10 or 15 yards. Other penalties against the defense give the offense an automatic first down, and, conversely, such penalties committed against the offense can cause them to lose a down. Some of the fouls that are most commonly called against an offending team include: false start, holding, offsides, delay of game, illegal use of hands, clipping and chop blocking. Officials signal a penalty by tossing a yellow flag towards or onto the field, after which the officials will concur and the referee makes the final determination as to whether or not an infraction was committed. The offended team has the option to accept the result of the play (during which the penalty was committed) by declining the penalty.

Offense – The offense is the team with possession of the ball, that is attempting to score. There are complicated rules regarding offensive formations. At least seven offensive players are required on the line of scrimmage on every play. The other players have the option of lining up anywhere behind the line, and the exact number of running backs, wide receivers and tight ends will vary from play to play, dependent upon the game situation. The offensive line is made up of five players who are there to protect their passer and clear the way for runners. These players are the Center, Guards (2) and Tackles (2). The offensive linemen generally don’t handle the ball. The quarterback is the player who receives the snap during most plays, and serves the leader for the offense, calling plays as they are relayed to him from the sidelines. The quarterback is responsible for starting the play by either passing to an eligible receiver, or running with the ball himself.

Offensive Backfield – The offensive backfield is the region of the playing field that is protected by the offensive line, or the players who line up in this area. Alternatively, offensive backfield refers to the of the players who line up behind the offensive line. These generally include the quarterback and two running backs, although there can potentially be anywhere from zero to three running backs used in any particular play. The quarterback is responsible for starting the play, when he receives the ball on the snap after which he will either pass the ball to a running back (or run himself) or for passing plays, pass to an eligible receiver. The running backs are called either halfbacks or fullbacks, with the fullback serving as the lead blocker in most cases. The halfback, in contrast, generally runs more. Running backs may either have a specific route to run, or concentrate on blocking.

Offensive Holding – Offensive holding is a penalty is which an offensive player grasps a defender in an attempt to hinder his ability to cover another player or to advance toward the ball. A foul in which an offensive player keeps a defender from advancing by grasping him with his hands or arms. Offensive linemen are allowed to use their hands provided that they keep them to the inside of a defenders body, but if they get to the outside of the defender's body, it becomes a penalty. The most frequent cause for this offense is a player grabbing a part of a defensive player’s jersey or his arms. If an offensive player wraps his arms around the defender, it will be called as offensive holding. Offensive holding results in a ten yard penalty for the offending team, and the down is replayed. The defense may also be called for holding, which results in a five yard penalty and automatic first down.

Offensive Line – The offensive line is the collective term for the five offensive players who line up at the line of scrimmage prior to the start of a play. The offensive team is the team that begins a play in possession of the ball. The offensive line consists of one center, two guards, two tackles and one or two tight ends. The center, as the name implies, lines up in the very center and is the player who snaps the ball to the quarterback. In many cases, the center is also responsible for coordinating the actions of the offensive line. Tackles serve primarily as blockers on running and passing plays, while tight ends are generally more of a mix between a blocker and a pass receiver. Offensive linemen are not eligible receivers, and consequently, may not catch the ball. They can run the ball, although it is rare that they are employed to do so.

Offensive Pass Interference – Offensive pass interference is a penalty that is called on an offensive player for unfairly preventing a defender’s chances of intercepting a pass, or for pushing a covering defender away to gain an advantage in catching a pass. In the NFL, the penalty for offensive pass interference is ten yards and an automatic first down. The defense may also be called for defensive pass interference, in which a defensive player attempts to interfere with an eligible receiver’s ability to make a fair attempt at catching a pass. Offensive pass interference rules apply from the time the ball is snapped until the ball is touched. Some of the actions that may constitute offensive pass interference are: blocking downfield by an offensive player prior the ball being touched, initiating contact with a defensive player by shoving or pushing him to create separation while attempting to catch a pass, or driving through a defensive player who has already established his position on the field.

Officials –Officials are the people who are responsible for maintaining order and enforcing rules during a football game. Although they are often referred to by the generic term, referee, in reality there are seven officials who operate on the field during professional and college football games, each with different titles and responsibilities. These include the Referee, Head Linesman, Line Judge, Umpire, Back Judge, Side Judge and Field Judge. The referee, or head referee, is responsible for the overall supervision of the game and making the final call when there is a discrepancy or disagreement. So that they may be easily recognizable, all officials wear a black and white vertically striped shirt with white pants. While the (head) referee oversees the entire game, and the umpire judges blocks from where they initially occur, the other judges are spread out over the field and are responsible for watching for penalties that occur in their area. The head linesman and his chain crew mark the forward progress of the ball.

Off-Season – In the NFL, the off season consists of the off time between the Super Bowl and the first game of the season. As of 2002, this season consists of a four game exhibition season (also called a pre season) that runs from approximately early August until September, a 16 game regular season that runs from September through December or early January and a 12 team playoff tournament that begins in January. The season ends with the two top teams facing off in the Superbowl during early February. Players are still held to a schedule of events during the off season, including appearances and some individual training, with mini-camps and the officially recognized Training Camp that takes place in July and August. During the off season, the Scouting Combine, trading and free agent signing period, and the NFL draft all occur.

Offside –Offsides is a penalty (or foul) that is called when a defender extends any part of his body into the neutral zone prior to the ball being snapped. A penalty is a sanction against a team for a violation of the rules. This foul is nearly always committed by a defensive player, but may be committed by the offense as well. If an offensive player is lined up in the neutral zone, than an offside foul would be assessed on him. The penalty for an offsides is five yards against the offending team. When an offside foul occurs, it is only announced at the conclusion of the play, which does not stop. The non-offending team has the option to choose to decline the penalty, instead taking whatever yardage was gained on the play. The referee signal for an offside foul is to place both hands on the hips with the elbows pointing outwards, as for a neutral zone or encroachment infraction.

Off-Tackle –Off tackle is a strong side running play in which the half back follows the fullback through the gap that has been created by the tackle and the tight end. In this play, the fullback will block the outside linebacker in most cases. Alternatively, the fullback may run to the outside of the tight end. An off-tackle play requires that the offensive tackle and the tight end use specific blocks in order to create a place for the running back to get though. For this reason, there is often a coded discussion at the line regarding formation. One of the more common variations on this play is called a power off-tackle, which is a version that is used with a pulling guard, and employs a double team at the off tackle area, a kick out block- typically by the fullback and a lead block by a pulling guard.

Onside Kick – An onside kick is a short, hard to catch kickoff that is usually employed by a team that is behind in points when time is running out. The receiving team has a presumption to a kicked ball, unless it is fumbled or muffed; however, when a kickoff travels ten or more yards, it can be recovered by the kicking team. An onside kick is one that is kicked in a way that favors recovery by the kicking team, in order to avoid giving the ball away. Additional conditions must be met in order for the ball to be recovered. The ball must be a free kick and must cross the receiving teams restraining line. The kicking team may regain possession of the kicked ball, but may not advance it an must not interfere with any attempt by a receiving player to catch the ball while it is still on the fly.

Open Up Holes – The primary duty of the offensive line on a running play is to push the defensive linemen back to create a gap for the ball carrier to run through, which is known as opening up holes. The offensive line positions include one center, two guards, two tackles and one or two tight ends. These players are not eligible receivers, so they cannot catch the ball, although they may choose to carry it. In many cases, the center is responsible for directing the offensive line in their plays. The primary responsibility of offensive guards is to block on both running and blocking plays to work trap or sweep plays. Offensive tackles play on the outside of the guards, and tackles have the important responsibility of protecting the quarterback’s blind side from defenders. Tight ends play next to the tackles, serving as a mix between a blocker and wide receiver. All of these players collectively work to open up holes for their ball carrier to get through.

Open Receiver – An open receiver is one who is not being covered or who has gotten away from his coverage and is able to get a pass. An open receiver can be any one of them on the field, including a wide receiver (flanker or split end included) or a tight end. Wide receivers are some of the most agile players on the team, and it is their responsibility to get open by creating space between themselves and defending players. Although tight ends were traditionally considered blockers, they now work as more of a combination wide receiver and lineman. Although typically very strong and larger players, they must also be fast and agile enough to run pass routes and create openings so that they can catch passes. Tight ends who work in the hybrid position of halfbacks will have more blocking responsibilities and less opportunities to run pass routes.

Option – An option is a play by the offense that allows the quarterback to choose whether to run, pass, or pitch the ball. It is unpredictable and hard to defend against, but rarely used in the NFL because of the speed that it requires from the quarterback, and the risk of injury to the quarterback due to the increased amount of tackling and the reduced protection that he receives in the option formation. Option offense is a generic term that can refer to a variety of offensive systems that are all characterized by a predominance of option running plays that are used in these schemes. Option offenses are useful for managing the game clock. Option offenses rely on timing and deception for their success. At the center of all of these plays is the option run, which is a complicated running play that has two variations, the double or triple option. With a double option run, there are two potential ball carriers, whereas with the triple option, there are three.

Out of Bounds – Out of bounds is the area outside of the sidelines and the end zone outside of the field of play. The sidelines are the longer boundary lines and the end lines are shorter boundary lines that designate the playing area. The lines themselves are also considered out of bounds. The end zone is the scoring area that extends ten yards beyond each of the goal lines to each end line, and includes the goal line but not the end line, which is out of bounds. In order for a player to legally catch a ball, he must establish both feet as in bounds prior to the catch. In some cases, a skilled receiver is able to make a catch and touch both feet into the field of play before he falls out of bounds with the ball. If a player catches a ball in the end zone, he must also have both feet inside of it. The clock is not stopped when a ball or player goes out of bounds, unless this occurs during the last two minutes of either half of a game.

Out of Bounds at Snap – a five yard penalty called when a player enters the field of play after the ball is “Snapped”

Outside – toward the “Sidelines”

Overtime – In the event that the regulation game time ends with a tie score, an extra period of play, called overtime, is added; this period is 15 minutes in the NFL, though the game ends after the first score by either team. Prior to the start of the overtime period, the captains meet with game officials for a coin toss to decide which team will kick off to the other. During the regular season, if the overtime period ends with neither side having scored, the game is called a draw. In some cases, a replay can be used to decide a winner. During playoffs however, because a tie is not allowed, additional fifteen minute overtime periods must be added until one team or the other scores. College and high school football follow a different overtime procedure that is sometimes called a ‘Kansas Playoff’ in which each team takes turns with possession of the ball, attempting to score.