They're unexpected, make an impact and we're still searching for explanations

So the marketing department of Distell does have a sense of humour. I've just decoded the meaning of their good-value brand Obikwa: Our Bottles Instantly Kill Wine Anoraks.

The label features a stylised bird from African art, but a black swan would have been more appropriate.

Nassim Nicholas Taleb was one of the few financial gurus who foresaw the crash of 2008. He compares the susceptibility of the global economic system to statistical outliers to the discovery of black swans in Australia by Europeans, who had thought all swans were white. Taleb defines black swans as events with three attributes: "They lie outside the realm of regular expectations; they carry an extreme impact; and human nature makes us concoct explanations for their occurrence after the fact."

The Obikwa shiraz 2009 is a black swan. Unexpected is an understatement, with audible gasps from the anoraks when it was acclaimed "best value" at the recent Global Trading Shiraz Challenge run by Wine magazine.

At "not much more than R20", according to winemaker Michael Bucholz; around R23 a bottle, according to the Distell press release; and a rip-off R24.95, according to tasting panel chair Christian Eedes, it is currently rewriting the value-for-money proposition for SA wine and having an "extreme impact" on those producers asking more for a bottle than the cost of a case of Obikwa.

As for explanations as to why it won, Bucholz says "having access to vineyards and cellars in winemaking regions across SA gives us the blending opportunity to put a lot of value into the glass".

That is the vinous equivalent of Taleb's contention that "Almost every major idea in conventional economics fails under the modification of some assumption . Take the notion of comparative advantage, which has oiled the wheels of globalisation. The idea is that countries should focus on 'what they do best'. So one country should specialise in wine, another in clothes, even though one of them might be better at both. But consider what would happen to the country if the price of wine fluctuated. A simple perturbation around this assumption leads one to the opposite conclusion. Mother Nature does not like over-specialisation, as it limits evolution and weakens the animals."

This focus on specialisation saw pinot noir planted ferociously in Walker Bay, now renamed the Hemel-en-Aarde Valley, in an attempt to become more fashionable. The argument then was that, being the most southerly vineyards, they had the most suitable terroir. When vineyards were established even further south at Elim on the way to Cape Agulhas, that argument was changed to Hemel-en-Aarde's having appropriate soils.

But Distell has another black swan: a Two Oceans pinot noir 2009, which retails for not much more than Obikwa. Clearly, Distell is the sub-prime scourge of pricey Stellenbosch.