The offside rule is frequently criticized, but its original purpose was precisely to prevent boredom in football. Since its consolidation, defensive tactics have always emerged to exploit its loopholes, making the game more monotonous. The 2026 World Cup reignited the debate about this controversial element, especially after disallowed goals, such as the one from Colombia against Portugal, which seem unfair and destroy promising attacks.
Origins and First Adaptations
The first version of the rule was established in 1863, being quite simple: any player positioned ahead of the ball was offside, following the model of rugby. The initial objective was to curb the so-called 'player in the bathtub'. However, the result was the opposite: athletes sought to dribble past all opponents or shoot at goal, forcing teams to adopt rigid tactical schemes, such as 1-1-8 and 2-2-6, resulting in very few goals.
The first alteration occurred in 1866. The rule was modified so that offside was triggered only if the receiver of the pass had fewer than three opponents between themselves and the goal. This change allowed coaches to position attackers further forward, encouraging passing over dribbling and valuing the midfield. Initially, the game gained dynamism, but soon a new problem arose: defenders and attackers became static, waiting for the play to be created by the midfield, and football became tedious again.
Tactical Evolutions and Regulatory Changes
The situation changed thanks to the British coach Jimmy Hogan, who popularized the idea of giving more roles to attackers. They began to have to drop back to attract markers and open up spaces, an innovative notion at the time. Subsequently, teams developed the 'offside trap', notably used by Arsenal under the command of Herbert Chapman. This tactic consisted of moving defensive blocks beyond the attacker's line, leaving him offside at the moment of the pass. The abuse of this trap led to excessive interruptions and low goal scoring in England in 1925, with an average of only 2.58 per match.
In response, during the 1925/1926 season, the rule was adjusted: only two players between the attacker and the goal were needed for him not to be offside, popularly known as not being 'the last man'. This weakened the trap, raising the number of goals in the English Football League from 4,700 to 6,373 in the following season.
The Third Rescue and Catenaccio
Starting in the 1950s, the 4-2-4 formation became popular, using four defenders to nullify attacks and two midfielders to link up with the attack, leaving exploitable wide spaces. The Brazilian national team, winner of three Cups (1958, 1962, and 1970), took advantage of this flexibility. Carlos Alberto Torres' goal in the 1970 final illustrates how empty space was used after Pelé dominated the ball.
As a counterpoint, less intense teams sought balance with the 1-3-3-3 formation, proposed by Austrian coach Karl Rappan. This formation introduced the 'libero', whose primary function was to cover the gaps left by the defenders. This defensive approach, nicknamed 'Swiss lock', was refined by the Italians as 'catenaccio' (or 'correntão'), where the libero also initiated counter-attacks with long passes. With the retreat on the rise, the libero facilitated the use of the offside trap, but the problem of few balls and many interruptions returned, culminating in the 1990 World Cup, with an average of only 2.21 goals per game.
In June of that year, during the World Cup, the International Football Association Board (IFAB) promoted a new change, valid for the following season. Offside became almost what it is today: the player was in a regular position if he was on the same line as the penultimate opposing defender, unlike before, when he needed to be completely behind him.
Modern Refinements and Technology
With tactical evolution, catenaccio lost relevance and the libero was gradually replaced, as individual confrontation began to favor the attacker. The 4-4-2 formation consolidated. In 2005, offside was refined to require that a part of the body capable of touching the ball was in front of the defender, invalidating, for example, an extended arm. The rule regarding a player being in an irregular position without interfering in the play was also clarified, which helped make games more fluid.
The introduction of VAR in 2017 aimed to correct human errors in offside calls. However, the technology generated the challenge of slowness in reviews, as seen in an 8-minute check in the FA Cup in 2025. This spurred the most recent change: the semi-automatic offside system, which is already being implemented in Brazil and will be mandatory in Série A starting from the second half of 2026, using cameras and artificial intelligence to speed up checks.