How do you know which is which; and how do you know when the natural order has truly been subverted ?

Well, first you have to know what the natural order is. And that requires the help of the physicists and other scientists.

What a scientist cannot explain may or may not be a subversion of the natural order. (What a scientist can explain may or may not also be a subversion of the natural order - some scientists can be trapped into providing justifications for incorrect versions of events - but it's still a useful filtering tool) Or it may be a thing that the physicist will have to update his model of physics to explain.

...it's not an easy question.

For example, I personally don't know much about that dancing sun event, but the fact that (according to Wikipedia, at least) it has not been recorded by any cameras or other instruments leads me to believe that human psychology, rather than divine intervention, was responsible.

That's not impossible. (I don't know much about it either; it was linked from the wikipedia article on 'miracle').

That said, in your estimation, approximately how many miracles of that kind are occurring on Earth per year ?

Ummm... if I had to guess... I'd guess less than one. I wouldn't venture a guess as to how much less than one, though.

Agreed. So, when we talk about miracles, let's stick to unusual acts of divine intervention.

Defining whether a given event is or is not an unusual act of divine intervention may be tricky; but fair enough, let's go with that definition for the moment.

Furthermore, there are many other works of literature with even better writing; for example, the Odyssey, Moby Dick, or, more recently, Harry Potter. Presumably, you don't believe that these works describe real events; but if so, why not ?

You're right; nothing that's written in the Gospels can raise it to a status of higher than 'plausible'. Many clear works of fiction also reach the status of 'plausible'; in order to reach the higher status of 'probably true', one needs a certain amount of external verification.

I find a good deal of that external verification in the fact that a number of people, in whom I place a great deal of trust, and at least some of whom are known to be better at identifying truth than I am, have told me that it is true.