How technology helps football linesmen

Offside technology is a new thing in the world of football. Football tournaments often use manual offside, although they are also starting to apply offside technology. Many football matches have become controversial because of goals the referee disallowed for offside. In addition, line judges also often make wrong decisions, causing losses for both the host and the opposing party.

Therefore, technology is needed to detect offside automatically so that it is expected could provide the right decision without harming both parties. There were some studies in various journals that discussed this offside method, including research by Sirantanita et al. (2017). In their research, they said that linesmen are sometimes unable to see the crucial scenes to suggest judgments due to limited human vision. Therefore, according to them, it is important to implement an automatic offside system. In his research, he used the automatic saliency method and installed four cameras on both sides of the center line to capture scenes of players with the ball. So that it can determine the offside decision from the movement of the player with the ball being played. This experiment is applied by the authors in 33 official FIFA tournaments held in Europe in 2016 and has obtained an output of 138 times offside showing an accuracy of 93.33%.

In addition to the research examples above, FIFA has developed an offside technology also that will be used at the FIFA World Cup 2022 match in Qatar. In the 2022 World Cup match, automated or semi-automated offside technology has begun to be implemented. FIFA announced the use of semi-automated offside technology for the 2022 World Cup in early July 2022. This technology follows the success of VAR (Video Assistant Referee), which was implemented at the previous FIFA World Cup 2018 in Russia. This semi-automated offside technology is a supporting tool for video match officials (VAR) to make quicker, more precise, and more accurate decisions.

Before the FIFA president announced the use of this technology, FIFA tried it first in official FIFA matches, namely the 2021 FIFA Arab Cup in Qatar and the 2021 FIFA Club World Cup in Abu Dhabi, United Arab Emirates. As a result, the semi-automated offside technology was successfully used and implemented in the match. FIFA also works closely with leading companies such as Adidas and various partners and working groups in the field of Innovation Excellence and Technology Providers. FIFA has spent the last few years implementing VAR technology, including the use of this semi-automated offside technology.

The way this semi-automated offside technology works uses 12 tracking cameras that are installed under the roof of the stadium. These cameras track the movement of the ball and players up to 29 points on each player’s body. The official ball for the Qatar 2022 World Cup Al Rihla, which is used at the 2022 World Cup, is also equipped with a special sensor to help detect offside. The sensor located in the center of the ball will send data up to 500 times per second. Thus, kick-point detection can be done precisely. Data from player and ball tracking supported by artificial intelligence will be combined and provide an offside warning to match officials. This warning will be sent every time the ball is received by a player who is in an offside position. Then, the video match official will validate the warning before passing it on to the referee on the field. When the referee blows the offside whistle, a 3D image will be displayed on the stadium screen and television screens, to show the offside position of the players during play. After that, the referee will watch for a few minutes and decide right then and there whether offside or not. This technology can also be applied to VAR which detects whether a goal has occurred, the ball has gone off the field line or a handball that the referee often does not see. FIFA claims the whole process can be done in a matter of seconds, although it takes less time to decide, an average of 70 seconds.

Thus, the use of sophisticated semi-automated offside technology is expected to assist the referee in making fair decisions regarding offside in all matches in the ongoing FIFA World Cup 2022. Hopefully, this technology can be applied in all official FIFA apart from the 2022 FIFA World Cup. Apart from that, it can also open up researchers around the world to develop this technology for the future.

By: Fathur Rahmawanto

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