The Monty Hall simulator, 12/2015, by Jeff Martin.  jm@islandalien.com

This program simulates multiple rounds of the famous "Monty Hall Problem" by Steve Selvin. 

https://en.wikipedia.org/wiki/Monty_Hall_problem

Click the CheckBox to step through 1 round at a time, or leave unchecked to play 100 rounds at a time.



The riddle goes something like this.

You are a contestant on the game show, "Let's Make a Deal".

Monty Hall shows you 3 doors.

Behind one of the doors is a Car.

Behind the other two doors is a Goat.

Monty then asks you to choose a door.

You randomly choose for example door number 1.

Monty already knows which door the Car is behind and then opens one of the doors you didn't pick with a Goat behind it, say for example door number 2.

Monty then asks you if you would like to change your choice to door number 3.

Would you change your choice to door number 3, or keep your original choice of door number 1?

The correct answer is to ALWAYS change your choice.

Why?

Basically, this means that only if you choose the door with the Car as your FIRST choice (not easy since the odds are 3 to 1) you will automatically LOSE because your compulsory second choice will always be a Goat. 

The alternative is if you choose either of the two Goats as your FIRST choice, (a little easier to do because the odds are 3 to 2) you will always get the Car as your second choice because Monty's Goat has already been removed from the available choices.

On avearge, if you always change your choice you will win more often.


