What is Offside in Football – Guide to Understanding the Rule and Its Tactical Implications

The offside rule is one of the most debated rules in football. It is also one of the most confusing rules for beginners and people who recently started to watch the beautiful game. But, as confusing as it may be, the rule serves a good purpose. To keep the game dynamic and entertaining and to prevent unfair advantages.

There were many times where offside calls brought on huge controversies and debates. In 2017, Real Madrid met Bayern München. The first leg ended in a 2-1 win for Los Blancos, and by the end of the regular time in the second leg, Bayern was up 2-1, bringing the aggregate to 3-3. The game went to extra time, where Cristiano Ronaldo scored twice from offside position, yet the referees did not call it. This is just one case of a huge controversy led by offside calls, and in this article, we will explore what the offside rule is, how it evolved and what are the tactical implications.

Understanding the Offside Rule in Football

The Offside Position

There are two things to consider here. The offside position, and the offside offense. First, a player is in an offside position if any part of his body, head, or feet is closer to the opponent’s goal line than both the ball and the second-last opponent. This means that, for a player to be in an offside position, he has to be closer to the goal than the last field player of the opposing team.

For a player to be onside, then between him and the opposing goal line, there have to be at least two opposing players. The goalkeeper (usually) and another field player.

Look at the diagram. The player that is offside is in front of the goalkeeper, but behind the last defender. So he is closer to the opponent’s goal line than both the ball and the second-last opponent. The other blue players have at least two opponents between themselves and the goal. So they are not offside.

The Offside Offense

By itself, being in an offside position is not an offense. A player may sit in an offside position and not be penalised. But think of it as not being able to take part in the game. The rules state a player that is in an offside position cannot be actively involved in a play. This means that a player in an offside position cannot:

• Play or touch the ball played by another player in the same team
• Make an obvious action which clearly impacts on the ability of an opponent to play the ball

There are some exceptions though, and a player can become actively involved in a play if he is offside but receives the ball from a goal kick, a corner kick or a throw-in. Another important exception, which also has a tactical implication, is that you cannot be offside if you are in your own half.

The offside is signaled by the assistant referee, or linesman, by raising his flag. This is one of the main reasons the assistant referee sits on the sideline, because his perspective is much better suited for spotting offsides than the central referee.

VAR, Semi-Automated Calls and Offsides

VAR was introduced in the major leagues in the 2017-2018 season. Before that, the offsides were called as the linesman spotted them stopping the play right away. The big problem is that offsides are hard to spot on the go, especially in high-speed plays, such as transition moments.

If the assistant referee incorrectly calls an offside and stops a play that could have resulted in a goal, it’s easy to see why both players and fans would feel frustrated. The same goes if the assistant referee would fail to spot an offside, and the play would cause a goal.

VAR introduced the ability to go back and review a play, and overturn a decision or a goal. With this ability, referees are not forced to decide that will impact the outcome of the game on the spot. Therefore, you often see offsides occurring, but the game is not interrupted. Referees are instructed that, when VAR is available, and they are not 100% sure of an offside call, it is better to abstain and the play will then be reviewed by VAR to confirm their suspicions or not.

Some leagues took this a step further and implemented the semi-automated offside technology. It will also be available in the Premier League starting with the 2024/2025, but the implementation is not yet finished. The new technology uses dedicated tracking cameras mounted underneath the roof of the stadium to track the ball and multiple data points of each individual player calculating their exact position on the pitch. When an offside is suspected, it alerts the VAR referees and they just need to confirm the decision.

What is the Purpose of the Offside Rule in Football?

The offside rule was mainly implemented to keep the game dynamic and entertaining to watch. The main point of this rule is to prevent goal hanging. Goal Hanging is when a player sits close to the opponent goal, regardless of what is happening on the pitch, to receive a pass that bypasses the entire defense and easily score.

You might imagine why watching a forward being stuck goal hanging during the entire game and receiving a simple pass that puts him in a one-on-one situation with the goalkeeper cuts off the drama and excitement of a proper attacking play.

Tactical Implications of the Offside Rule

The offside rule has tactical importance in the game of football. First, by placing your back line, you decide how much space you give opponents to exploit. If a team is implementing a low block, then it does not give much space for runs in behind them, because a forward does not have space or momentum to get in behind. But it gives the team room to exploit.

On the opposite side, by employing a high block, a team allows their opponents to run in behind, if they have the speed and timing to do so, but reduces the space for the opposing team to build-up and play. You might wonder why some teams deploy a back line that is as high as the midfield line when defending. Remember the exception to the offside rule by being in your own half?

By placing the back line on the midfield line, you cram your opponent in their own half. If one player would sit behind that line, he would be in the opposing half, and offside. But if Hansi Flick would push his defenders even higher, then he would allow space between the defenders and the midfield line for an opposing player to sit and wait to be launched.

Defenders and coaches can also leverage the offside rule to set up the offside trap. In the offside trap, defenders step forward when a pass is made to catch the opposing team offside. You can check out this article on the offside trap to better understand this mechanic.

Conclusions

The offside rule is one of the most confusing rules for someone new to watching the beautiful game of football. Yet it is one of the most important rule that make or break the game. It adds a new dynamic, prevents the game from being stale and boring, but it is also tough to implement. Technologies such as VAR and semi-automated offsides make the rule easier to implement and more fair. Understanding the offside rule is crucial both for coaches, spectators and players and I hope this article shed some light and made this aspect of the game easier to understand.