Abstract
SocTech (Soccer Technology) encompasses any innovations that are made to enhance performance, fairness, and player safety. Goal-line technology and VAR (Video Assistant Referee) are two widely known SocTechs that promote fairness in the game. However, due to their semi-automation, they remain susceptible to being replaced. Emerging technologies that reduce manual errors now allow referees to track 7,000 to 10,000 points on each player at all times[1]. Moreover, SocTech has been heavily used in soccer training.For instance, virtual reality (VR) technology helps players improve reaction times and optimize decision-making by allowing them to repeatedly practice in-game situations without the risk of injury. Tests showed significant improvement, with pre-training scores of approximately 16 points increasing to 20 points post-training[2]. SocTech has also revolutionized health tracking with innovations like the Heart Rate Meter and the Accelerometer, helping players extend and optimize their careers.
Introduction
My fondest memories involve me playing on a soccer field. Soccer has always been my biggest passion—from watching Chelsea FC’s Eden Hazard dribble through the world’s best defenders to recreating his iconic goals with my friends. I remember watching every match with my friends. Our eyes were glued to the television, waiting for a moment of genius from players that would change the tempo of the game.
The first experience of soccer technology was when I was given an official 2014 World Cup ball, the Brazuca. My excitement knew no bounds as I leapt onto my computer and searched for the different benefits of the new ball. The difference in drag speeds and curl compared to other balls was immense. This introduction to SocTech provided me with a hint to the upcoming massive technological changes in the soccer world.
Innovative designs in soccer have elevated from soccer balls to system creations like VAR and Goal Line Technology. The introduction of AI and VR in training has also helped boost players’ skills with systems like Tactic AI, which creates in-game situations to increase player awareness and reaction. Although these technologies have optimized the sport, they have been criticized for the slow removal of the human touch.
Ensuring Fair Play: The Evolution from VAR to the Dragon System
Referees hold the power to make decisions in soccer that determine the outcome of a match. Even though they are impartial, human error or bias can lead to wrong decisions. This led to the creation of the Video Assistant Referee (VAR) system. VAR was designed to eliminate decision-making mistakes, but this semi-automated system has been criticized for causing stoppages in games and failing to completely eradicate incorrect decisions. SocTech’s continuous evolution has addressed this problem with the introduction of an improved video assistant referee, ‘The Dragon System’, which ensured fairness and improved the viewers’ experience.
VAR: Boon or Bane?
The need for these technologies was evident in the Bundesliga (German League) match between Dortmund and Ingolstadt. The game featured three officiating errors that contributed to Ingolstadt losing 2-0. Despite Dortmund’s victory, the controversy prompted defender Mats Hummels to claim that nearly 10-15% of the goals scored would not stand if VAR were implemented correctly in matches [3]. VAR plays an important role by using virtual reality to draw lines on the field. However, these lines drawn on the field are not perfectly defined, as they are based on VR rather than physical reality[4,] leading to inaccurate decisions. This issue stems from the parallax error problem. The camera used for the system does not adjust differently for angles, leading to wrong offside calls when viewed from a certain angle [4].
The Dragon System
VAR remains in the semi-automated phase, providing referees with recorded footage to make a decision, which leads to game stoppages and pressure on officials to make quick and accurate calls [4]. SocTech has improved this system by incorporating iPhones to improve fairness. This groundbreaking system is being used in the Premier League for the first time this season [1]. The technology uses a network of iPhones positioned throughout the Premier League stadiums, tracking 7,000 to 10,000 points on each player to minimize errors [1]. Known as the “Dragon” system, it captures up to 200 frames per second instead of the usual 50-60 frames per second, making decision-making more accurate. This helps avoid parallax error, but its semi-automation still makes it important for the referees to make decisions faster, leaving room for human error. Furthermore, a machine learning(ML) system running in the background analyzes player movements and learns from them to develop a fully automated offside detection system for future use [1].
Figure 1: The “Dragon” System Tracking Software [1]
Enhancing Officiating: The Evolution of Goal Line Technology
The Dragon System revolutionized controversial in-game decisions like fouls and offside, while Goal Line Technology revolutionized the decision-making process pertaining to the legitimacy of a goal. Soccer rules state that a goal is only awarded if the entire ball inside the goal; even if a part of the ball is on the line, the goal does not stand. This rule used to be enforced by referees looking at the goal from a distance, relying on the 30-60 second human eye capture speed. Criticism of this manual method led to the introduction of balls with sensors that detected when they crossed the goal line [5]. Additionally, the goal line was embedded with magnetic field lines to accurately determine when the sensors went inside the goal [5]. This automated yet invasive technique could not provide unquestionable video proof that the ball had crossed the goal line [5]. This issue was resolved with the innovation of a video-based automated system known as Goal Line Technology.
Goal Line Technology (GLT)
Goal Line Technology uses six cameras, with two placed parallel to each goal and the remaining cameras placed behind the goal perpendicular to the goal frame [5]. These cameras are connected to the supervisor node that computes the correct decision after reviewing all the footage sent to it. This entire process is automated, ensuring fast and accurate decisions. The accuracy of GLT was tested in real matches of the Italian Serie A Championship. The ball detection software embedded in the GLT system was successful in the 19-match test as the greatest challenge came from body parts, logos, or a combination of colors in player uniforms disrupting the ball detection procedure [5]. The results yielded a correct detection of 33 goal events with only one false positive occurrence [5]. These convincing results have led to the adoption of GLT in the top leagues across Europe—the Premier League, Bundesliga, La Liga, Serie A, and Ligue 1.
Although these automated decisions may allow a fairer game, Jonathan Ford (Chief Executive of the Football Association of Wales) has expressed reservations about the creating an automated system that may eradicate the referee’s power of autonomy from the game [6]. Historically, the referee’s decision has been an integral part of the sport; therefore, such forms of technological control must be handled with care. The SocTech involved in the game should primarily assist—not replace—referees in their decision-making process [6]. The presence of an automatic system like GLT may reduce referee autonomy, but it prevents game stoppages and allows fairer decisions, as humans are unable to estimate the position of a fast-moving soccer ball, making it difficult for referees to evaluate different goal events with certainty [5].
Figure 2: Goal Line Technology System [5]
Scouting with Precision
Discovery of talent is an integral component of building strong teams. Teams like Real Madrid, Liverpool, and Southampton have great training programs that help them scout talent. These famous training programs attract hundreds of youngsters aiming to become the next Van Djik or Bale. China’s advancements in SocTech have allowed scouts to use computer video analysis to measure players’ running speeds [2]. The running speed analysis helps in optimizing player placement in positions and allows coaches to determine roles best suited for each player. Moreover, this can be used extensively in player selection as players more suited to be central defenders tend to have a lower high-intensity running speed, but a better middle- and low-intensity running speed than wingers [2]. This analysis acts as a differentiating factor between various players and allows the coach to identify“‘true potential”.
A study by Yongzhi Yang from the Hainan College of Economics and Business also highlights the importance of athletic ability index weight for positional selection. This index represents the athletic ability of a player at six different positions through a hexagonal graph [2]. This evaluation uses AI and reflects the versatility of the player, influencing the arrangement of players’ position on the field [2]. The use of AI to calculate this index also helps determine physical capabilities as coaches focus more on high-intensity evaluations rather than middle- and low-intensity evaluations [2] leading to imperfect placements of players. This can be seen in current times through players like Manuel Neuer and Sergio Ramos, who both started as strikers but moved to goalkeeper and center back respectively due to previous suboptimal position selection.
AI can also evaluate the mental ability of different players by analyzing their shot choices during the game. The study conducted by Yang compares players’ competitive ability percentages between amateurs and semi-professionals, which found that semi-professionals had a metric [AI] of 90%, while amateurs had a metric of 75% [2]. This result can be seen as successful as there is a large gap in the competitive level between the two groups. These analytics can be used to differentiate between prospective players and choose optimal players for a team.
Train Hard or Train Smart?
The importance of improvements in soccer goes hand in hand with the spirit of competitive play. The need to be the best in the league pushes players to train extensively and perfect every aspect of their game. The main debate in soccer revolves around whether players who train harder are better or players who have talent. However, the advancements in SocTech have brought up a new discussion between training harder or training smarter.
A study conducted by Meng Su from the Henan College of Transportation tested the effectiveness of VR training by comparing players’ performance pre-training and post-training. VR allows players to recreate in-game situations, helping them master game skills and strategies [7]. The experimental values were recorded post-VR training, while the control was taken pre-training. Using AI, the results found that VR training led to a significant increase in a player’s tactical awareness, offensive passing, co-defense, complementary awareness, and convergence awareness [7]. The overall pre-test score was 16.93, while the post-test score was 20.66[7]. Since this result could also have been achieved through normal training, another test was conducted using the students from the same college. The control group underwent normal training, and the pre-test scores were 17.89 and the post-test scores were 19.45[7]. This difference between both the groups proved that the effect of VR training was significant in improving player skill. The smarter way to train is primarily with VR and AI. This constant practice in VR will enable players to ingrain situations into their minds and apply them on the field.
Another important use of AI in soccer training is perfecting set pieces. Set pieces are moments in the game when fouls are committed, or the ball goes out of play leading to free kicks, penalties, and corner kicks. These types of cases can be pivotal during a game, offering the teams a higher probability of scoring a goal compared to normal play. Moreover, corners and penalties tend to be taken from the same spots, allowing teams to practice and perfect these situations. TacticAI is a new AI that helps improve these set pieces. It maps these different scenarios and outcomes into a graph and recommends the correct techniques that should be used to score a goal [8]. An example of this use of AI is when a cross is delivered from a corner kick, a player has the different shot choices of a header, volley, and acrobatic kick. Alternatively, they could also bring down the ball and try to dribble it or pass it to another player. This new system was presented to the coaching staff at Liverpool FC, and 90% of the staff favored these new innovative ideas over the older existing strategies [8]. This system can be extremely effective and favorable, but improvements are still being made. Petar Veličković, a staff research scientist at GoogleDeepMind, stated that this AI could be used in general play and other sports like American football and hockey as well [8].
Figure 3: TacticAI: The expected goal probability for different player positions [8]
Tracking the Internal and External
The use of SocTech is essential for health tracking. This tracking is done using systems like HRM (Heart Rate Monitor), LPMS (Local Position Measurement System), and ACC (Accelerometer) [6]. The HRM helps in monitoring player stamina and VO2 intake, helping players determine the optimal training to maintain or improve their health. All these technological devices used in soccer are used to find muscular fatigue (MSF), distance covered (DC), speed (SP), and acceleration and deceleration (AD). By analyzing all these metrics,a regime can be created to maximize player performance without the risk of burnout [9].
Advancements in soccer training technology have also led to the development of tracking software like semi-automatic multiple-camera video technology (VID) and the Global Positioning System (GPS). GPS is a new technological implementation that is growing exponentially. It uses time signals that are provided by orbiting satellites to pinpoint the locations of each player during a match [10]. This method produces similar results as the VID system, which uses cameras to track players around the pitch and allows analysts to study their movements and team interactions [11]. Both technologies measure a player’s external load, helping improve individual, position-specific, or team-related goals [11]. The data allows analysts to get a comprehensive assessment of the overall physical demands on a player’s body through the measurement of DC and AD. This allows them to monitor fatigue levels and match readiness to prevent injury and allow lengthy careers. Although both these systems are extensively used by teams, they are susceptible to systematic errors that lead to the overestimation of distance traveled by players.
Figure 4: GPS system [13]
Conclusion
My fascination with soccer began with small improvements in a soccer ball. In the past ten years, minor changes in a ball’s drag speed and curl have led to the creation of smart balls that project the curve and speed on the ball [12]. Moreover, the competitive spirit that comes with soccer has led to innovation that improves player speeds, athletic ability, and decision-making by optimizing data analysis and training regimes. Technologies like VAR, GLT, and the “Dragon” system have helped eliminate bias by ensuring players and fans fairer outcomes in matches, with decisions being more accurate and transparent, reducing human error and controversy. The hidden technologies behind player analysis and health tracking continue to shape the game, enabling many young players to enjoy longer careers than the “OGs”. The development of SocTech continues, with new ideas that aim to replace GPS technology, such as Fitogether and Sportlight [14]. Fitogether is a hyper-accurate tracking system, while Sportlight measures player acceleration and monitor health, and performance [14]. The growth of SocTech is both imminent and necessary, sometimes even solving problems created by previous technologies—such as the shift from VAR to the Dragon System. This rapid advancement of SocTech showcases the fast but cautious pace of innovation, as well as the potential of technology to redefine the beautiful game [AI] while preserving human skill and viewership.
Links to Further Readings:
[1]Tamir and M. Bar-eli, “The Moral Gatekeeper: Soccer and Technology, the Case of Video Assistant Referee (VAR),” Frontiers in psychology, vol. 11, pp. 613469–613469, 2021, doi: 10.3389/fpsyg.2020.613469. “https://uosc.primo.exlibrisgroup.com/permalink/01USC_INST/273cgt/cdi_doaj_primary_oai_doaj_org_article_bea26a086f154b0888f4008f77a288e6”
[2] Dowsett, “The English Premier League Will Ditch Its Hated VAR Offside Tech for a Fleet of iPhones,” WIRED, Aug. 14, 2024. https://www.wired.com/story/the-english-premier-league-has-a-new-iphone-powered-offside-detection-system/
[3] Su, “Research on intelligent soccer teaching and training model integrating virtual reality technology,” Applied mathematics and nonlinear sciences, vol. 9, no. 1, 2024, doi: 10.2478/amns.2023.2.00875. https://uosc.primo.exlibrisgroup.com/permalink/01USC_INST/273cgt/cdi_scopus_primary_2_s2_0_85175297264
[4] “Google DeepMind’s new AI assistant helps elite soccer coaches get even better,” MIT Technology Review. https://www.technologyreview.com/2024/03/19/1089927/google-deepminds-new-ai-assistant-helps-elite-soccer-coaches-get-even-better/
Multimedia Links:
[1]Crystal Palace FC. Why do footballers wear GPS vests?. (July 7, 2017). Accessed: Sept. 16, 2024. [Online Video]. Available: https://www.youtube.com/watch?v=oAjRA4m2mFE
[2]TECH Revolution. Google DeepMind and Liverpool FC Unveil AI Soccer Coach – TACTIC AI – And it’s Genius!. (Mar. 21, 2024). Accessed: Sept. 16, 2024. [Online Video]. Available: https://www.youtube.com/watch?v=oAjRA4m2mFE
[3]The Men In Blazers Podcast. This Ref’s Dramatic VAR Pause is Absolute Perfection. (May 16, 2022). Accessed: Sept. 16, 2024. [Online Video]. Available: https://www.youtube.com/watch?v=oAjRA4m2mFE
Bibliography
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[8] “Google DeepMind’s new AI assistant helps elite soccer coaches get even better,” MIT Technology Review. https://www.technologyreview.com/2024/03/19/1089927/google-deepminds-new-ai-assistant-helps-elite-soccer-coaches-get-even-better/
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