> They understand that opening one door does not change the odds that they picked the wrong door at first. Yes, they had 1-in-3 chance of getting it right orig

> They understand that opening one door does not change the odds that they picked the wrong door at first. Yes, they had 1-in-3 chance of getting it right originally, and that won't change if they do nothing... But of course that means there was a 2-in-3 chance it was one of the other two doors, and one of those has just been eliminated by being opened, meaning the 2-in-3 chance of being right is represented by the remaining door.... So, do you stick with your original door which has 1-in-3 chance of being right, or switch to the other door which you now know has a 2-in-3 chance of being right ? The key is that they are now being offered the choice to make a better informed choice than they had originally.