Take it in stages

When you make your choice, you have a 2/3 chance of being wrong and 1/3 chance of being right.

Agreed?

Then, the reveal makes no difference whatsoever to the chances of the door you chose being the right door or not - it's still 1/3, making the chances of the door you chose not being right 2/3.

So you switch to load the odds in your favour.

Of course, sometimes you'll switch and lose, about a third of the time in fact, and you only play the game once :)

Posted By: Old Man, Nov 2, 16:57:11