This year, the ball shouldn’t have that kind of impact on which team wins the World Cup. In wind tunnel tests, Goff found that Telstar 18 has a very similar aerodynamic profile to the 2014 Brazuca ball, which flew without the wobbles of the Jabulani. The Jabulani was the first ball to have six seams and despite having a roughened surface, it was too smooth, says Goff. When the Brazuca was released, it had 68 percent more seams than the Jabulani to help change the airflow around the ball. The Telstar 18 is even more improved. Instead of transitioning to laminar flow in the middle of free kicks, Goff found that the Telstar 18 goes through its drag crisis at a lower speed of 38 miles an hour.
On the other hand, replicas (sometimes called training balls or gliders) are designed to be just like the official match balls but are much cheaper. Their panels are often stitched rather than thermally-bonded and are made of a different material. However, they’re not necessarily less durable than official match balls. So, they’re the recommended option for most players. https://www.youtube.com/watch?v=j2Xn84L3Kcs
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