Altitude will impact ball speed at 2010 World CupCAPE TOWN, South Africa - The goalkeepers at next year’s World Cup should consider their geography before getting on the field.
A new study done by Adidas shows that the altitude at the World Cup will have an impact of up to 5 percent on a ball’s speed. That means, according to the study seen by The Associated Press, that a free kick from 20 meters (22 yards) during the final at the Soccer City stadium in high-altitude Johannesburg will reach the goal line 5 percent faster than it would at the Moses Mabhida stadium in sea-level Durban. That translates into a free kick traveling at an average of 126 kph (78 mph) at high altitude to 120 kph (74 mph) at sea level.
But if playing at high altitude has some drawbacks for goalkeepers, it also has its advantages. A goal clearance that travels 60 meters (yards) in Durban will travel 63 meters (yards) in Johannesburg. Even more importantly, free kick specialists will not be able to put as much spin on the ball because the thin air offers less grip to change course. Among the nine host cities during the World Cup, Soccer City stands at 1,694 meters. The beachside Moses Mabhida stadium is at only eight meters.
Other stadiums higher than 1,000 meters include Bloemfontein at 1,351, Pretoria at 1,330, Polokwane at 1,230 and Rustenburg at 1,153. Apart from Durban, Cape Town and Port Elizabeth are also coastal. Even more important than the speed of the ball will be the speed of players adapting to the different altitude levels. To get an edge, most of the major teams have already decided to set up camp as high as possible, mostly in and around Johannesburg. It is easier for players to adapt coming down to sea level rather than moving up to high altitude.
Adidas traditionally produces new balls for each World Cup and they invariably cause controversy since new technology almost always makes for a speedier ball that puts goalkeepers at a disadvantage.
This time, Adidas is convinced the Jabulani, which means “to celebrate” in isiZulu, will sail true because small dots on the surface improve reliability in the air.
World Cup lore shows that maybe the ball does matter. At the maiden World Cup in 1930, Argentina and Uruguay supposedly could not agree what ball to use, so they compromised and used a different ball in each half.
With its ball, Argentina raced to a 2-1 lead at halftime. But the Uruguayans bounced back with their ball and won the final 4-2. AP