Not every World Cup goal is a classic. Sometimes a half-hearted shot goes in as a result of little more than goalkeeper error. And on those occasions, goalies may be inclined to find an excuse.<\/p>\n\n\n\n
During the 2026 tournament, some members of what is jokingly referred to as the \u201cgoalkeepers\u2019 union\u201d have pointed toward the performance of the ball. Joe Hart, a former England goalkeeper and serving BBC pundit, noted after one blunder: \u201cThe ball is coming into the keepers a lot faster than it feels when it comes off the foot.\u201d<\/p>\n\n\n\n
But are his concerns justified? The Conversation turned to John Eric Goff, who has been studying the physics of World Cup balls for two decades and previously wrote about what to expect<\/a> from the Trionda ball being used at the 2026 FIFA World Cup.<\/p>\n\n\n\n Colleagues of mine at the University of Tsukuba in Japan took the World Cup ball, put a little hole in it, stuck it on a rod, attached force sensors and then set it up in a wind tunnel to obtain all kinds of aerodynamic data. They sent that data to me to look at what the trajectory modeling for the ball suggested about how it would perform in comparison to its predecessors.<\/p>\n\n\n\n Central to the performance is the airflow around the ball and how it changes as the speed of the ball increases. For the Jabulani ball used in the 2010 World Cup, for example, this airflow change happened at a speed that was right in the middle of typical free kicks and corner kicks. That caused problems for goalkeepers, as it moved in the air unpredictably as a result.<\/p>\n\n\n\n Among the recent World Cup balls we tested, Trionda has the lowest critical speed at which that airflow change takes place. That led us to predict free kicks and corner kicks with fairly consistent, stable flight. <\/p>\n\n\n\nWhat did your lab tests predict?<\/h2>\n\n\n\n