Inside FIFA

What is it?
How does it work?
How was it tested?
FAQs
FIFA's Living Football
What is it?
Semi-automated offside technology is a support tool for the video match officials and the on-field officials to help them make faster, more reproducible and more accurate offside decisions.
How does it work?
The new technology uses 12 dedicated tracking cameras mounted underneath the roof of the stadium to track the ball and up to 29 data points of each individual player, 50 times per second, calculating their exact position on the pitch. The 29 collected data points include all limbs and extremities that are relevant for making offside calls.  
Al Rihla, adidas’ official match ball for Qatar 2022™, will provide a further vital element for the detection of tight offside incidents as an inertial measurement unit (IMU) sensor will be placed inside the ball. This sensor, positioned in the centre of the ball, sends ball data to the video operation room 500 times per second, allowing a very precise detection of the kick point.
By combining the limb- and ball-tracking data and applying artificial intelligence, the new technology provides an automated offside alert to the video match officials inside the video operation room whenever the ball is received by an attacker who was in an offside position at the moment the ball was played by a team-mate. Before informing the on-field referee, the video match officials validate the proposed decision by manually checking the automatically selected kick point and the automatically created offside line, which is based on the calculated positions of the players’ limbs. This process happens within a few seconds and means that offside decisions can be made faster and more accurately.

After the decision has been confirmed by the referee on the pitch, the exact same positional data points that were used to make the decision are then generated into a 3D animation that perfectly details the position of the players’ limbs at the moment the ball was played. This 3D animation, which will always show the best possible perspectives for an offside situation, will then be shown on the giant screens in the stadium and will also be made available to FIFA’s broadcast partners to inform all spectators in the clearest possible way. 
How was it tested?
The semi-automated offside technology set-up and workflow have been successfully trialled at numerous test events and live at FIFA tournaments, including the FIFA Arab Cup 2021™ and the FIFA Club World Cup 2021™. 

During these matches, the new technology was able to support the video match officials by helping them to make more accurate and more reproducible offside decisions in a shorter period of time. 
FAQs
Here you can find answers and further clarification to the most frequently asked questions.
Globally, an offside check by the VAR takes an average of 70 seconds.
 Instead of selecting the correct kick point and drawing the offside line manually, the video match officials team, by using semi-automated offside technology, only needs to validate the proposed decision by visually checking the automatically selected kick point and the automatically created offside line, which is based on the calculated positions of the players’ limbs. This process happens within a few seconds and means that decisions can be made on offside calls faster and more accurately. However, complex incidents or multiple incidents that occur at the same time can require a more thorough review of the situation. 

If the video match officials do not agree with the kick point and/or offside line proposed by the system, they can manually select the kick point and use the existing tools to draw the offside line.  
The new technology can support the video match officials in the offside decision making process whenever the ball is received by an attacker who was in an offside position at the moment it was played by a team-mate. For all other offside incidents (e.g. interfering with an opponent), there is no change to the decision-making process and it is up to the referee to make a judgement call.
FIFA is the sole owner of the collected tracking and ball data.
After the decision has been confirmed by the referee on the pitch, the exact same positional data points that were used to make the decision are then generated into a 3D animation that perfectly details the position of the players’ limbs at the moment the ball was played.
Based on the test results gathered during the three-year testing phase, semi-automated offside technology is currently the most accurate offside support system available to video match officials. In addition, the system provides consistency in the placement of offside lines, especially in situations where the shoulder or top part of the arm determines the offside line.
According to Law 11 of the Laws of the Game, the offside line is drawn at the goalscoring body part of the second-last defender closest to the goal line. If the ball is closer to the goal line than the second-last defender, then the part of the ball closest to the goal line defines the offside line.
In the event that semi-automated offside technology does not work correctly, the video match officials can still use other well-known offside support tools, such as crosshair or triangulation.
In very tight offside situations, where the offside decision is different between two frames, the video match officials will check the exact first touch of the moment the ball was played by using the inertial measurement unit data from the sensor inside the ball and then select the correct frame of the footage based on the kick point.
Once the validation process is complete for the automatically selected kick point and automatically drawn offside line by the video match officials, the video assistant referee informs the referee on the pitch about the decision via the audio communication system.
FIFA's Living Football
In this episode of FIFA's Living Football, we take a look at semi-automated offside technology that will be used at the FIFA World Cup 2022™ in Qatar. 

Chairman of FIFA's Referees Committee, Pierluigi Collina and FIFA's Director of Football Technology and Innovation, Johannes Holzmüller explain how the technology will offer a support tool for the video match officials and the on-field officials to help them make faster, and more accurate offside decisions. Watch the Living Football show below.
Last updated: Monday 17 July 2023 at 16:33