Suppose you're participating in a TV quiz show and you make it to the final round. The quiz master shows you three closed boxes; two of them are empty, but the other one contains the super prize of $1,000,000.
He asks you to make a choice... When you make your choice he opens one of the rejected boxes and shows you it is empty.
Now he gives you the opportunity either to stick to your first choice or to pick the other box.
What should you do? Or does it not matter at all because the odds are now fifty-fifty?