Atlas robot's World Cup performance secret: grass training

The secret behind humanoid robot Atlas's World Cup appearance was grass training. To walk, run and deliver a ball on a real outdoor soccer pitch packed with tens of thousands of fans without falling, Boston Dynamics rented an actual soccer field and trained Atlas on turf — far from the smooth floors of an indoor laboratory.

Boston Dynamics, the robotics subsidiary of Hyundai Motor Group, released a behind-the-scenes video and technical blog Wednesday through its SNS channels detailing how it developed Atlas's halftime performance at the FIFA World Cup 2026.

Atlas took the stage at the round-of-16 halftime show on July 5, mimicking goal celebrations by world-class soccer players and delivering a ball to the referee on the pitch. The appearance drew wide attention as a rare instance of a humanoid robot performing before a live crowd in a real stadium — not a controlled laboratory. Some international media called it "a sight never seen before in World Cup history."

The newly released footage focuses on how the team pulled it off. A soccer stadium is a difficult environment for a robot to navigate. The ground is not perfectly flat, and turf varies in elasticity and friction from spot to spot. An outdoor stadium adds further variables: sunlight, temperature, communication interference and the movement of people nearby. Simply repeating a fixed set of motions was never going to be enough to put Atlas on that stage.

Boston Dynamics tackled the communication problem first. Standard Wi-Fi-based connectivity is unreliable in a World Cup stadium filled with tens of thousands of fans, so the team built a dedicated private communication channel to ensure a stable link between Atlas and its operators. The company also tuned the robot's systems and control functions to keep it moving normally under intense sunlight and high temperatures.

Grass was among the biggest challenges. Atlas has been trained and tested primarily in indoor environments, whereas a soccer field presents a high risk of the robot's feet catching or slipping. The condition of the ground beneath the turf is also uneven. For a humanoid robot where even a small loss of balance can lead to a fall, it is a demanding stage.

To address this, Boston Dynamics modeled how the robot's feet interact with and respond to a grass surface, then incorporated that data into the training process. The team also rented a local park soccer field to test Atlas's movements on real turf. The released footage shows Atlas walking and running across an empty pitch, repeating its motions over and over.

The goal-celebration movements were not simply played back from a motion file, either. A technique called retargeting was applied to adapt human movements to Atlas's physical structure. Directly mapping a person's arm and leg motions onto the robot can conflict with its joint geometry and center of gravity, so the movements had to be rebuilt in a form Atlas could actually execute.

Reinforcement learning also played a role. Across thousands of parallel simulations, the robot learned to maintain balance through repeated cycles of success and failure. This raised Atlas's reaction speed and balance control so it could respond instantly even in unpredictable conditions like those of a real stadium. Whole-body control technology — which coordinates all of the robot's joints to move as a single unified system — was layered on top.

That is why Boston Dynamics views the performance not as a publicity stunt but as a technology validation exercise. Delivering a soccer ball and executing a celebration routine requires the robot to handle objects, maintain balance and adapt its movements to the surrounding environment — capabilities that map directly onto what is needed to move parts on a factory floor, operate equipment or work alongside people. The adaptability Atlas demonstrated at the World Cup stadium was, in effect, a proving ground for its potential deployment in industrial settings.

"The most important thing we thought about while developing Atlas was making the robot capable of performing virtually any task," said Seth Davis, senior program manager at Boston Dynamics. "I think the robot's movements need to intuitively show what a robot can do for people, and what role it will play in the future."

Davis said that executing precise, stable movements in a crowd-filled stadium requires the same capabilities needed to work in a complex factory environment. A manufacturing site is also a space where workers, equipment, parts and movement paths are constantly changing. The adaptability Atlas showed at the World Cup stadium was, in effect, a test of its readiness for future deployment on the industrial floor.

Boston Dynamics said it plans to keep developing a broad range of technologies so that Atlas becomes not merely a robot that performs impressive movements, but an essential component of real manufacturing environments.