Rory McIlroy is not having a good season on the golf course. A year ago the wunderkind from Northern Ireland finished second in the rankings. This year he did not even qualify for the end-of-season Tour Championship. But he is not the only one fluffing his shots. Adidas, the German sportswear maker, has cut its full-year net income guidance by almost a tenth, to between €820m and €850m. That sent its shares down 4 per cent on Friday. One of the reasons it cited was the poor state of the global golf market.

It seems that golfers the world over are not stocking up on new drivers and irons. But that is not the only reason why Adidas revised its forecasts. Continued weakness in a range of currencies from the Russian rouble to the Argentine peso against the euro played a part. This is not surprising. Currency effects had already wiped 3 per cent off group sales in the first half from a year earlier. Adidas’ German rival Puma, which also books its sales in euros, is suffering too.

More worrying for Adidas was a hiccup at one of its new distribution centres in Russia, its third-biggest market after the US and China. Its strength in Russia gives it an advantage that helps to offset the global superiority of its biggest rival, Nike. The US sportswear group commands more market share in all of its key markets and has operating margins of 13 per cent, nearly two-thirds more than Adidas. What is more, as Adidas moves away from its flagging Reebok brand, especially in the US, it is Nike, not Adidas, that is picking up the share.