by Michalis Michaelides

In previous instalments of this blog series, we introduced the concept of skeletal tracking, explored the technology that makes it possible, and analysed the transformative benefits of skeletal tracking data in virtual recreations. 

The power of data goes beyond the spheres of applications mentioned above, and we now turn our attention to how skeletal tracking technologies have been revolutionising officiating in sport, with a focus on football (soccer).

From Goal-Line Technology to Semi-Automated Offside: A Steep Evolution

The evolution of officiating technology in football has been rapid. Hawk-Eye pioneered the introduction of Goal-Line Technology (GLT) in 2015, providing speedy and accurate decisions of whether the ball has crossed the goal line. This was shortly followed by Video Assistant Referee (VAR) solutions, which introduced video replay to allow officials to use video footage to make in-game decisions. 

Today, we have entered the era of Semi-Automated Offside Technology (SAOT) – a groundbreaking innovation that would not be possible without skeletal tracking.

The Role of Skeletal Tracking in Officiating

Officiating in football has long relied on ball-tracking systems, similar to those used in Electronic Line Calling (ELC) in tennis or the GLT technology mentioned above. Ball tracking alone, however, cannot reliably clarify a player’s position to determine whether an athlete is on or offside. This is where Hawk-Eye’s SkeleTRACK comes in.

SkeleTRACK captures real-time, high-fidelity movement data of players, supporting automated event detection on the pitch. SAOT in football, for instance, uses between 10 and 14 dedicated cameras positioned around the stadium to track 29 skeletal points on every player. To put this into perspective, traditional performance data capture analyses around 600,000 data points per team, whereas skeletal tracking increases this number to an astonishing 172 million data points.

The Gold Standard in Football Officiating

Hawk-Eye’s SAOT has been deployed from major domestic and international tournaments in professional football since 2022.  The technology seamlessly integrates ball tracking and skeletal tracking to determine offside positions within seconds. By minimising the time required for VAR-assisted offside calls, SAOT significantly reduces game interruptions, enhances match flow, and most importantly, increases accuracy by eliminating human error.

How SkeleTRACK Improves Officiating

The technology behind SkeleTRACK further advances the accuracy and speed of offside officiating by:

• Increasing tracked body points: unlike traditional center of mass tracking, which uses just one point on a player's body, SkeleTRACK monitors 29 key points, allowing for significantly greater accuracy in offside determinations.

• Providing real-time tracking: instantaneous skeletal tracking has drastically reduced decision-making times for offside calls, ensuring faster and fairer officiating.

By combining these benefits, SkeleTRACK powers SAOT, enabling referees to make faster, more precise decisions –enhancing fairness and reducing controversial offside calls in football.

What’s Next? The Future of Automated Officiating

Looking ahead, the joint venture between Hawk-Eye and FIFA is focused on the generation of algorithms to automate the detection of on-pitch events with a view to optimising decision-making. By continuously improving the speed and accuracy of player tracking, we are driving the next evolution in officiating –where decisions are made (almost) instantly, with minimal interruptions to the game.

As football continues to embrace innovation, skeletal tracking is proving to be a game-changer, shaping the future of fair and transparent officiating.

Did you find this article useful? Check the other chapters of our blog series via the links below.

1. The Future of Data Tracking in Sport
2. Defining the Sports Experiences of Tomorrow: Data-Driven Virtual Recreations