The main restriction would be to pick "important" predictions, whatever "important" means here.
I don't know if there is any useful algorithm here. The space of possibilities is vast, black swans lurk at the outskirts, and Murphy is alive and well :-/
You can try doing something like this:
and you get your universe of "events of interest" to assign probabilities to.
I doubt this will be a useful exercise in practice, though.
Yes, upon reflection, it seems that something along these lines is probably the best I can do, and you're right that it probably will not be useful.
I'll give it a try and evaluate whether I'd want to try again.
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