Kantor on 02 December 2010
It makes logical sense, the 2/3 probability, if you consider the whole thing as one problem. But I'm not really convinced.
The way I see it is as follows:
Three doors; a car and two goats.
You choose a door. Doesn't matter which.
Host reveals a goat.
END OF PROBLEM A.
Two doors; a car and a goat (what I'm saying is that this is an entirely different puzzle. By opening a door and revealing a goat, the host has changed the situation, and the choices you can make).
You are now choosing between the car and the goat. It's a 50:50 chance.
(Former) Lead Moderator and (Eternal) VGC Detective 
