[It's an obvious joke so Keltham doesn't get upset at the proposed unfair bet; if it was 1 in 10,000 it'd have happened already to some plane flight, and would be in the handbook.]

"Low-probability as in non-mundane, or it expands our view of the mundane.  Changes which sort of things we think can happen to us going forward.  Isekai would count, aliens would count, some weird side effect of a solar flare would not count."

(It's an obvious joke so Keltham doesn't get upset at the proposed unfair bet; if it was 1 in 10,000 it'd have happened already to some plane flight, and would be in the handbook.)

"Low-probability as in non-mundane, or it expands our view of the mundane.  Changes which sort of things we think can happen to us going forward.  Isekai would count, aliens would count, some weird side effect of a solar flare would not count."