A new study done by Adidas shows that altitude at the World Cup will have an impact of up to five percent on a ball's speed.
That means, according to the study, that a free kick from 20 metres during the final at the Soccer City stadium in high altitude Johannesburg (5700 feet) will reach the goal line five percent faster than it would at the Moses Mabhida stadium in sea level Durban.
Other high altitude venues include Bloemfontein (4430 feet), Pretoria (4362 feet), Polokwane (4034 feet), and Rustenburg (3782 feet). Apart from Durban, Port Elizabeth/ Nelson Mandela Bay and Cape Town are the other sea level venues.
The faster speeds mean that goalkeepers have less reaction times. This could offer an advantage to those who love taking open field potshots. However, the thinner, drier air is less conducive to bending of the ball. This does not favour free kick specialists like David Beckham and Andrea Pirlo.
Lets take the USA. In Group C with England, Slovenia, and Algeria.
The USA has the least travel and acclimatization:
All the US matches are in the high altitude venues. Acclimatization may not really be a issue because at that altitude (less than 7000 feet) there is no visible effect on oxygen saturation rates. Plus, the US will get plenty of time before the matches to dissipate any lingering effects. The high altitude venues are close to each other (Rustenburg - Jo'burg/ 76 miles, Jo'burg- Pretoria/38 miles) so travel time is much less and therefore fatigue will not be a factor. The USA can consider the highveld their home grounds for the next two weeks.
The Algerians on the other hand are the ones who have to contend with the most travel and acclimatization. They start their campaign against the Slovenians in high altitude Polokwane (the northernmost venue), then travel down to Cape Town (at SA's southern tip, a distance of 1085 miles) to meet the English, and then climb back up to Pretoria (Cape Town- Pretoria/ 914 miles) to face the USA.
The Slovenians have the first two games in high altitude Polokwane (Algeria) and nearby Rustenburg (USA) and then travel to coastal Port Elizabeth/ Nelson Mandela Bay to finish up with the English. It is easier to acclimatize traveling down from a higher altitude.
The English once they finish their encounter with the USA in Rustenburg travel down to the coast to take on the Algerians in Cape Town and then end their group stage fixtures in Port Elizabeth/ Nelson Mandela Bay against the Slovenians.
Rustenburg, June 12th: The USA vs England
A Frank Lampard or Steven Gerrard shot struck at 80 miles/hour in Cape Town will travel at approximately 84 miles/hour in Rustenberg. Look for those cannonball artists to test Tim Howard with open field blasts early before his hands warm up in the cold air. On the other hand those swinging Ashley Cole crosses that were so amply on display against Arsenal last weekend might take a straighter trajectory which might make it easier to deal with. The faster ball also means that it will be easier to mistime tackles leading to fouls. Chances of own goals go up. Nerves before the first match could also impede ball control.
Johannesburg, June 18th: USA vs Slovenia
Not much in terms of travel for both teams with the Slovenians facing the Algerians in nearby Polokwane. By now both teams should have adjusted better to the faster ball. The Slovenians as demonstrated against Russia and England (in a September friendly) are a team that can soak up quite a lot of pressure. They are quick and creative on the counterattack with Robert Koren, Andraz Kirm, and Necj Pecnic leading the way, relying on short quick passes. A majority of attacks emanate from both wings with crosses/passes peppered into the box for the quick footed Milivoje Novakovic and Zlatko Dedic.
Of the 20 goals scored in the qualifiers, 19 came from strikers and midfielders, none from set pieces. They graft goals relying less on open field shots or set pieces. The Slovenians also have a solid defense which gave up just six goals in the 12 matches with Samir Handanovic making some spectacular saves. The USA will have to make an adjustment to the more compact Slovenian style taking advantage of the faster ball speed.
Tshwane/ Pretoria, June 23rd: USA vs Algeria
The USA might face a tired Algerian team. The Fennecs will have traveled 2000 miles by then and face a harder adjustment to the higher altitude of Pretoria from sea level Cape Town. The second adjustment will be the ball speed. The same effort at sea level will make the ball fly in Pretoria, so ball control might be a tad more difficult. The match's intensity will be a factor and it could prove decisive in which team goes through to the group of 16.
Unlike the Slovenians, the Algerian defenders are quite adventurous, prominent on set pieces and push up front though their wing backs given any opportunity. Madjid Bougherra (Rangers), Nadir Belhadj (Portsmouth), and Antar Yahia (Bochum) are amongst the leading goal scorers. The 6' 1" Yahia and 6'2" Bougherra have already scored seven goals. Many of the Algerians ply their trade in the major European leagues with an appreciation of set piece opportunities and long balls. Going aerial is a big part of their game.
The Algerians rely on Wolfsburg's Karim Ziani and Nadir Belhadj who share free kicks and corners and have been quite successful at it. The $11m Ziani made a big splash in Eric Gerets L'OM squad as a creative playmaker in his three seasons at the club. Antar Yahia's game winner at Khartoum against the Egyptians came from a Ziani free kick. In the first match against Egypt, Belhadj's free kick was headed down by the 6' Abdelkader Ghezzal (Siena) as Algeria went on to beat the Pharoahs, 3-1.
Fatigue and ball control could be factors which favour the USA in their final match against Algeria.