How does the ball sensor work in the situation of canceling Croatia's equalizer?

The equalization situation in the 13th minute of injury at BMO Field in Toronto is the biggest controversy in the round of 16 so far. From Ivan Perisic's cross on the left edge into the penalty area, the ball flew past four players, respectively Igor Matanovic, Renato Veiga, and Mario Pasalic before Ruben Neves scored an own goal.

The key to the situation is determining whether Matanovic touched the ball or not. If not, the goal is valid. On the contrary, Pasalic was offside and the goal was canceled.

Through the built-in sensor in the Trionda ball, the referee determined that the Croatian player had touched the ball. In the post-match interview, Matanovic also thought "the ball lightly grazed my hair".

Afterwards, FIFA reported on the situation, confirming the referee's decision was correct. Besides, the World Football Federation also explains how the sensor in the ball works.

"Data provided by the Connected Ball Technology integrated into the Trionda ball has confirmed that Croatian player Igor Matanovic touched the ball with his head," the report reads. "This allows the referee to accurately determine the offside situation and not recognize the goal."

FIFA said the sensor is capable of recording any small collisions with the ball, then sending information to the VAR system in real time. A "heart rate graphic", a visual impulse marking the moment of contact with the ball, will be displayed to the television audience.

Previously, the sensor was effective in Sweden's fourth goal, in the 5-1 win over Tunisia from the first round of Group F. Initially, the referee determined offside with the scorer Svanberg. However, the sensor showed that the ball lightly touched intermediate player Alexander Isak, so Svanberg was no longer offside and the goal was recognized.

This technology originates from cricket, with the name snicko (short for snickometer), to assist the referee in determining whether the ball lightly touches the batter's bat or not. The system analyzes the signal and displays it in graph form. When there is a collision, no matter how small, the graph will appear a sharp peak, showing the moment the contact occurred.

The version applied by FIFA at the 2026 World Cup operates on the same principle. Inside the ball is a motion sensor microchip, recording ball touch data up to 500 times per second. Data is transmitted directly to the VAR room, to determine hand contact situations, fouls or identify the last player to touch the ball before a goal is scored.

This system has appeared at the 2022 World Cup, but is only a sensor made by ball sponsor Adidas, not part of FIFA's process. At that time, sensors confirmed that Cristiano Ronaldo did not touch the ball in Portugal's goal against Uruguay, even though he admitted he did.

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