At the 2026 World Cup, the referees on the field and the officials on the sidelines will rely on an unprecedented arsenal of technology to make crucial decisions. From calling penalties and spotting offside violations to reviewing red cards, the video assistant referee (VAR) system and semi-automated offside technology (SAOT) have been refined to an extraordinary level. This summer's tournament represents the most advanced use of adjudication tech in soccer history—and arguably across all high-level sports.
During each match, the pitch will be awash in sensors, cameras, and cutting-edge computer vision software. One particularly notable advancement is the use of digital twins. Every player has undergone a full-body 3D scan to create an avatar that precisely matches their height, limb length, and shoe size. These digital twins can be dropped into a virtual simulation of the game to determine exact positions relative to the ball, boundary lines, and other players. Officials can then use this data to spot infractions, assess penalties, and smooth out the edges of the beautiful game.
Even with these systems studying the action more closely than the human eye, flesh-and-blood referees remain central to the game. But when they get it wrong—which they do, as any fan will attest—and their decisions are challenged, officials can turn to the technology to correct mistakes, replacing subjective calls with objective truths. These systems are primarily used to catch major errors, such as checking if a player was offside during a play that resulted in a game-deciding goal. However, teams can also request reviews for less consequential plays, raising questions about the system's true value: Is it bringing an impartial eye to pivotal moments, or allowing the league to adjudicate tiny infractions by inches?
The Eyes Have It
FIFA and other worldwide soccer agencies have made their position clear: they want to eliminate big errors, but those inches also matter. Elements of this year's setup are similar to the 2022 World Cup, but with significant upgrades. Hawk-Eye remains the optical tracking provider, using its computer vision system to capture over two dozen skeletal points on each player at all times. This time, the system employs 16 high-resolution cameras—up from 12 in 2022—as FIFA director of innovation Johannes Holzmüller explained.
Like in 2022, that optical data is combined with advanced sensors inside the ball. Kinexon, a leader in sports wearables, again provides the match ball's digital brain. This year it includes an ultrawide-band and IMU sensor setup (accelerometer and gyroscope, the latter vital for capturing spin) that tracks the ball's precise location and any distinct touches, recording data points 500 times per second. Previously, the sensor sat suspended in the center using a string-based sling by Adidas. Now, Adidas has created a small bladder that holds the sensor along the inside wall of the ball. Maximillian Schmidt, Kinexon's cofounder, noted that vulcanizing the sensor inside the bladder with a plastic pouch is much more stable than the previous hooks and strings, which could break. Placing the sensor on the interior wall required counterbalancing to prevent wobbling from the added weight. Despite weighing only 13 grams, precise calibration ensures even tracking of every touch. Since the sensor is now at a point where it may be kicked directly, more robust impact testing was critical.
Combined, these optical and in-ball tracking systems will capture every nuance of all 104 World Cup games. But it's the high-tech assist borrowed from virtual reality that makes them even more accurate.
Digital Twins
During the lead-up to the tournament, all 2026 World Cup players underwent a 360-degree high-resolution scan from FIFA's tech partner, Lenovo. These scans are ingested into the Hawk-Eye system, replacing generic avatars previously used for offside and other VAR applications. Art Hu, Lenovo's global chief innovation officer, says these scans define body shape, muscle tone, and even shoe size with 1 to 2 millimeter accuracy—an order of magnitude improvement over ordinary avatars. The real challenge is applying a single scan taken while the player stands still to Hawk-Eye's skeletal pose data during active gameplay—running, jumping, sliding. The cost of a few extra inches of precision is enormous computing power and algorithmic tuning. FIFA tested the new setup at the Club World Cup and Intercontinental Cup in 2025, plus various youth tournaments over the previous 18 months.
Prior versions of digital twin tech already assisted VAR decisions for all goals and penalty kicks. The new version will also help review red-card penalties and incidents where on-field officials accidentally penalize the wrong player. VAR technicians can now overturn corner-kick decisions if the system detects the error and alerts referees via headset without delaying the game. (Some calls take longer and would slow the game, so VAR is not used for those.) Additionally, VAR can now send immediate alerts to sideline officials for obvious offside decisions, stopping play right away—a change from past arrangements that allowed play to continue and only stopped later for a notable event like a goal. Holzmüller is confident that the upgrades allow correct calls more often, even for nuanced decisions like “when there’s only one toe offside.”
Keeper Peeper
While most offside plays can be spotted via slowed-down broadcast footage, a handful occur at the precise moment between video frames. FIFA is determined to solve this by combining 3D scans and ball-tracking data—which captures positions 500 times per second, offering higher resolution than video's 60 frames per second—to supplement video footage for the most complete picture. Perhaps the most interesting feature is a “3D goalkeeper view” within VAR. This visualizer shows the goalie's point of view and uses digital inputs to determine if an attacking player in an offside position interfered with the keeper. This interference has long been illegal but hard to call accurately due to the number of players and field size. Hu points out broad applications for digital twin tech across sports, from officiating to athlete health and performance. As models become more powerful and computing costs drop, they'll only improve.
It's fair to wonder if the juice is worth the squeeze for gaining an inch or two of resolution on rare calls. Holzmüller admits that these advances, with all the technical and financial legwork, might only change a few calls throughout the tournament. But from FIFA's perspective, there's no question of value when it comes to the world's biggest sporting event. “We have to bring the best technology to the World Cup,” he says. “That’s our goal.”
Source:Ars Technica News