Offside (football)

Offside is a Law in football (soccer) which effectively limits how far forward attacking players may be when involved in play. Simply put, a player cannot gain an advantage by waiting for the ball with only the goalkeeper or last defender between him and the goal.

Application

The application of the offside rule is best considered in three steps; Offside position, Offside offence and Offside sanction.

Offside position

A player is in an offside position if "he is nearer to his opponents' goal line than both the ball and the second to last opponent," unless he is in his own half of the field of play. A player level with the second last opponent is considered to be in an onside position. Note that the last two opposing players can be either the goalkeeper and an outfield player, or two outfield players.

It is important to note that being in an offside position is not an offence in itself.


Offside offence

A player in an offside position is only committing an offside offence if, "at the moment the ball touches or is played by one of his team", the player is in an offside position and in the referee's opinion is involved in active play. A player is not committing an offside offence if the player receives the ball directly from a throw-in, goal kick or corner kick.

In order for an offside offence to occur the player must be in an offside position when the ball is touched or played by a team-mate; a player who runs from an onside position into an offside position after the ball was touched or played by a team-mate is not penalised. Similarly, a player who is in an offside position when the ball is touched or played by a team-mate may potentially commit an offside offence even if they run back in to an on-side position before receiving the ball.

Determining whether a player is in "active play" can be complex. FIFA issued new guidelines for interpreting the offside law in 2003 and these were incorporated in law 11 in July 2005. The new wording seeks to more precisely define the three cases as follows:

* Interfering with play means playing or touching the ball passed or touched by a teammate.
* Interfering with an opponent means preventing an opponent from playing or being able to play the ball by clearly obstructing the opponent's line of vision or movements or making a gesture or movement which, in the opinion of the referee, deceives or distracts an opponent.
* Gaining an advantage by being in an offside position includes playing a ball that rebounds to him off a post or crossbar or playing a ball that rebounds to him off an opponent having been in an offside position.

In practice, a player in an offside position may be penalised before playing or touching the ball if, in the opinion of the referee, no other team-mate in an onside position has the opportunity to play the ball.

The referees' interpretation of these new definitions is still proving controversial until this day, largely over what movements a player in an offside position can make without being judged to be interfering with an opponent.

Offside sanction

The sanction for an offside offence is an indirect free kick to the opposing team, at the spot where the offence occurred. Most referees use their discretion and let play go on if the "offended" team already has the advantage or ball, in order not to slow down play with redundant free kicks that achieve the same purpose of giving the advantage or ball back to the "offended" team.

Officiating

In enforcing this rule, the referee depends greatly on an assistant referee, who generally keeps in line with the second last defender in his relevant end (exact positioning techniques are more complex). An assistant referee signals that an offside offence has occurred by raising his flag in a manner that signifies the location of the offence:

* Flag pointed downwards: offence has occurred in the third of the pitch nearest to the assistant referee.
* Flag horizontal to the ground: offence has occurred in the middle third of the pitch.
* Flag pointed upwards: offence has occurred in the third of the pitch furthest from the assistant referee.

The assistant referees' task with regards to offside can be difficult, as they need to keep up with attacks and counter attacks, consider which players are in an offside position when the ball is played, and then determine whether the offside positioned players become involved in active play. The risk of false judgement is further enhanced by the foreshortening effect, which occurs when the distance between attacking player and the assistant referee is significantly different from the distance to the defending player, and the assistant referee is not directly in line with the defender. The difficulty of offside officiating is often underestimated by spectators. Trying to judge if a player is level with an opponent at the moment the ball is kicked is not easy: if an attacker and a defender are running in opposite directions, they can be two metres apart in a tenth of a second.


Offside trap

The offside trap is a defensive tactic. When an attacking player is making a run up the field with a team-mate ready to kick the ball up to him, the defenders will move up-field in order to put the attacker behind them just before the ball is kicked, hence putting the attacker in an offside position when the ball is kicked. Defenders using this tactic often attempt to bring an attacker's potential offside status to the attention of the assistant referee, typically by shouting or raising their arm.

The use of the trap is often derided as making for boring football. However, it can be a risky strategy as all the defenders have to move up together, otherwise the attacking players will not be in an offside position; if the offside trap fails, the attacking players will have an almost clear run towards the goal. The 2003 rule changes have made it even more perilous as a tactic.

One of the best-known defenders to employ the offside trap was Billy McCracken of Newcastle United. It is claimed his play pressured officials to modify the laws in 1925, reducing the required number of defenders between the attacker and the goal line from three to two.

The offside trap has become riskier since the 2003 law interpretation in which the definition of active play was made more stringent. Thus, teams attempting an offside trap are less likely to have an offside offence called when they have caught a player in an offside position if he was deemed to be not in active play.