The math is wrong in that Wikipedia article.

The article says, "Contestants who switch have a 2/3 chance of winning the car, while contestants who stick have only a 1/3 chance"

Here's where it's wrong. At the beginning, you have a 1/3 chance. Once the door is open, you have a 1/2 or 50% chance of being right no matter which decision you make. At that point, you are not choosing between three doors, you are choosing between two. The odds must be based on that.


>Off topic but still an interesting link I received today http://en.wikipedia.org/wiki/Monty_Hall_problem
>[ not to be read after returning from the pub ]