re: Marilyn vos Savant and the history of the Montel Hall question

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Again, the problem with this riddle is that the mathematical explanations always start with the premise that you must carry forward the old 33/66 probabilities from the first problem into the second. That is the cheat--you don't. The Monty Hall problem really is a 33/66 probability problem changed into a 50/50 problem, but discussed mathematically (incorrectly)after the basic premise has been changed as if it is still a 33/66 problem.

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Your logic here is incorrect, and the reason so many people have trouble with it.

It is still a 33/66 problem after one goat door is eliminated.

Look at it this way.

Host: You can either pick one door or two doors.

You obviously pick two doors.

Host: But wait; if you pick two doors, I will show you a goat behind one of your doors before opening your other door. Would you like to change to just one door?

Since you already know that at least one of the two has a goat, you wouldn't care and would go with the two doors anyway.

That's the exact math behind the problem as is. You are choosing between 1 door or two doors, one of which is revealed to contain a goat.