I'm pointing out is that there do exist some people who are more accurate than the others at assigning probabilities consistently, year after year. This is the real world phenomenon that needs explanation (though see below for caveats).

> Also, you cannot predict black swans

You don't have to exactly predict black swans to roughly estimate probabilities of events. As in, you don't need to enumerate exactly what could happen in the future, you do need to be aware of the possibility but some events are more likely than others.

Now, Taleb would say this is all nonsense because you can't meaningfully deduce a probability of a future event without knowing the denominator, that is look at all future possible worlds leading to outcome A as the numerator and (all future possible worlds leading to outcome B + worlds leading to A) as the denominator.

Which is strictly speaking very true and we are liable to fool themselves. Yet at the same time you can deduce that on aggregate people above the age of 80 have fewer years to live than people under 8... and if you were to predict how long someone would live based on their age, would you just throw your hands up and say it's impossible to know because of black swan events? Or might you look at actuarial tables and try to come up with a probability, especially if there's profit to be had in the form of selling insurance...

Taleb would counter that these predictions are fragile, that one day a black swan will come along and steamroll you when the next cosmic gamma ray event wipes out only the young and not the old, wiping out the past 200 years of gains.

Is that what you're referring to when you say that (super)forecasting doesn't work?