You can't predict any particular black swan, but you know they happen and you can attempt exploit the odds of it. Which is what Ycombinator, and any VC company for that matter, does.
The article mentions that Taleb believes the randomness of Black Swans is merely an appearance resulting from the lack of information. More information -- better information -- can improve predictions.
Besides, Alan Kay would suggest that the best way to predict the Black Swan would be to invent the Black Swan.
Look for things with fixed downside but unlimited upside. The opposite of this was LTCM's strategy of picking up pennies in front of a steamroller; NNT trolls Robert Merton throughout the book
Taleb's point is that unexpected outlier events are the ones that have the greatest impact. Prediction works because the next moment is usually not much different from the current moment.