Any math representing a physical thing requires a base line figure or figures that are physical to calculate.<quoted text>
Arguing probability doesn't require "observable evidence". It simply concludes given a set of circumstances what is more likely.
Of course you can construct a hypothetical scenario out of the abstract, but it has little meaning. Like calculating alternate universes, we can say if there are infinite universes , the probability that there are mirror repeats of Earth is high.
But this concept has no basis in reality.