“The simple picture is that Trionda may very slightly punish extreme distance, but it should reward clean technique and predictable flight,” says team member John Eric Goff, who researches sports physics and is an incoming professor of engineering practice at Purdue University.  “Goalkeepers, defenders hitting long passes, and long-range shooters are where I would look first for visible differences.”  Researchers used a wind tunnel to study the Trionda ball at the University of Tsukuba. TAKESHI ASAI, SUNGCHAN HONG, AND RICHONG LIU Adidas has been designing new balls for each World Cup since the 1970s. Some of the design changes in the first few decades were aesthetic: The 1986 ball featured graphics inspired by Aztec temples for the Mexico tournament, and 1994’s had space graphics in honor of the moon landing’s 25th anniversary. There were some structural differences too, such as upgraded foam cores and improved water resistance. But by and large, the balls used the same design of 32 pentagonal panels stitched together.  That changed in the 2006 World Cup in Germany, when Adidas introduced …