It's not that it's strange, it's that it is transparently silly to claim to precisely quantify in the absence of anything resembling sufficient information for the problem to be treated probabilistically.
How about this? I keep a running probability (e.g. a 32bit float) for the successful outcome of each future event I have absolutely no idea about. At first I make it 50%, but I gradually adjust with each result, such that I aim to minimize my bias. It might sound silly, but at the minimum it would encode some information about the kind of events I'm typically asked to predict. And I do expect it could end up something like 0.5642635 for a particular time in my life.
"Not even wrong." An event about whose outcome you by definition have no information ("I have absolutely no idea") is an event to which you cannot assign any probability, including by assuming it's a coin flip and then treating the assumption as axiomatic. It encodes no information whatsoever because there is none to encode, and it biases all future results because you're averaging over a range that includes "data" you made up.
I'm having trouble following your reasoning. "Not even wrong" typically is used to refer to something unfalsifiable, but I specifically provided an empirical process and even a mechanism to explain why it might work - a person in a given position would likely be asked to make predictions with a different base likelihood of success than a person in another position.
In any case, it is precisely my argument (and Scott Alexander's) that there are no events to which it is axiomatically impossible to assign probabilities.
A prediction based on no information is definitionally unfalsifiable.
I'm well aware of the nature of the argument, having been an SSC reader since long before the whole Cade Metz kerfuffle, and still being an ACX reader now - admittedly these days more to see what Alexander is on about lately; it's been some time since I've taken him seriously. A major reason why that's the case is because I've yet to see from any source a substantiation of that argument which is sustainable in the absence of a lot of handwaving. Granted, nobody waves hands like Scott Alexander! That's a lot of why I still find him so entertaining. But the handwaving is still handwaving.
Any jackass off the street can just not know things! If you want to get invited to the in-crowd's house parties, you're going to need to do a lot better than that.
