sports
Goalkeepers beware: Trionda World Cup ball hits ‘crisis’ point at certain speed
Some, like Luca Zidane, have been bamboozled and an academic paper bears out Joe Hart’s opinion about its movement

TL;DR
- Goalkeepers like Luca Zidane, Édouard Mendy, and Ahmed Basil are conceding goals due to difficulties reading the speed of the Adidas Trionda World Cup ball.
- Joe Hart believes goalkeepers are struggling because the ball comes off the foot faster than it feels.
- An academic paper titled 'Orientation-Dependent Drag Crisis and Flight Response of the Fifa World Cup Match Ball Trionda' explains the ball's behavior.
- The study found that at a certain velocity, the ball experiences 'drag crisis,' causing it to fly faster.
- The Trionda's design, with 'upstream seam and groove arrangements,' makes drag crisis possible at lower speeds.
- The drag crisis effect can be influenced by where the ball is struck (seam vs. panel) and altitude.
- FIFA highlighted the four-panel construction and deep seams of the Trionda as innovations for in-flight stability.
- Promotional materials from Adidas claim the Trionda ensures a 'more predictable trajectory,' but this contrasts with observations and past criticisms of balls like the Jabulani.