The name for the point where a probability changes

I'm not too sure where I stand on this subject. I've thought about it from time to time but never formed any good conclusions.Just out of curiousity, how would one interpret the following situation. It's a variation on the door/prize theme.You are told a prize resides behind one of 1000 doors. You go pick a door. Before you decide to open it, 998 doors are shown not to have a prize behind them, with only your door and one other remaining. You are then given the chance to change which door you want opened. Do you change it? Why? Is there a better chance that the door you haven't chosen has the prize?This goes out to anybody who wants to put forth their two cents.

I think those are the choices. I have a tendency to lean towards C. Here's why. It comes down to randomness. At the macroscopic scale, it seems the only element of randomness introduced is the result of the mind. Most, if not all, probabilities seem to be formulated under the tacit assumption that it is the mind that introduces the randomness, and most questions regarding probability can be formulated in terms of the mind.I shuffle a deck of cards. I then pick a card from the top of the deck. What are the chances of it being the Ace of Spades? Most people would say 1/52, assuming the deck has 52 cards. I would disagree. The chances are either 1 or 0, it either is or isn't the Ace of Spades. This can be clearly seen by another scenerio, in which someone shuffles the cards, looks at the top card, then sets the deck down. Someone else comes along and picks up the top card. Well, it's not going to chance from when the last person looked at it, so the chances of it being the Ace of Spades is either one of zero.I think the correct way to formulate the question would be: what are the chances that the mind, working through the body, has shuffled the deck in such a way that the top card is the Ace of Spades? The same can be said about the box behind the doors. The question shouldn't be, "what are the chances of the box being behind door number three?" It should be, "What are the chances that the person (mind) who was putting the boxes behind the doors chose to put it behind door number three?"Then the question is: is the mind a generator of randomness or deterministic? Just like Melchoir said, it comes down to whether there is randomness in this world. If there is, then probabilites are an accurate depiction of reality, if not, then they are only useful tools to aid humans with inadequate knowledge.Which one is it though? At our scale, it seems things are deterministic, barring the mind. At the quantum scale, treating particles are probability waves seems to accurately describe the world....I have to go, I'm not sure this was going anywhere anyway. Does what I am saying make sense to anybody out there?