I lost a lot of sleep last night reconsidering scenarios and situations, to no good end.
And, eventually, found myself agreeing that–and this is the only way I can put it without getting a sudden headache:
In the Monty Hall puzzle, as discussed in this post (see below “Original Post”), in two-thirds of all possible scenarios, the contestant will gain by switching doors when the host makes the offer.
In other words, the post itself is wrong–which means I was wrong. Period.
The whole situation still gives me a headache. I’m not willing to use the wording that “the remaining door you didn’t choose has a 2/3 probability of being the right door”–that makes me want to scream. If a second contestant shows up, sees the two doors and is told which door the original contestant chose, I’d still assert that the second contestant is equally likely to win by choosing either door.
But I’m wrong as to the facts for the original contestant. Hell, I’ve been wrong before.
Note: I wrote this as the very first thing I did on my computer this morning–before reading two additional comments. Now, after pasting this same text into the original post, I’ll go read the comments and add another one, admitting that Seth (and others) were right and I was wrong.
And then maybe go take some aspirin.