>Hi Al,
>
>>1. There are exactly 2 doors remaining.
>
>That's the point. 2 doors are remaining which means, there are more doors involved. They point is, you can't simply remove one door from this 3-door game, because statitistically, you don't know which one. If you remove one there's 1/3 probability, that you remove the door with the boat. This 1/3 is exactly, what must be added to the 50% probability of your 2-door game, ie. 0.5*1.33 = 0.66, the probability that changing gives you the right door.

Hi Christof - I see I missed all the action over the weekend :) This is an old statistical problem, and invariably there is confusion and disagreement on the solution, even when the problem is stated clearly (in which case the 2/3 solution is the right answer for the usually given 3-door problem).

In this case, from what I've read, both sides are right for the way in which they stated their solution - it's a matter of interpretation, unless the problem is stated more clearly - in this case, it appears the problem was not stated too clearly, so either answer is correct if based on the stated premises...