Up until recently I would have agreed with you wholeheartedly about this
but having spent a day trying to get my head around the Monty Hall Problem, I have realised I do not understand probability at all and that my opinion on such matters is totally worthless.
(leviticus no longer likes the cut of your gib on, Fri 22 Apr 2011, 14:36, 1 reply)

The issue with that..
.. is that additional information is introduced during the game.

Your chance of picking the "prize" first time is 1 in 3.

However, after being shown one "wrong" choice, you will never choose that one. Therefore, if you switch you can never lose unless you were right to start with. Therefore if you stick you will win one in 3 and if you switch you will win every other time (2 in 3).

The lottery does not take away any neighboring balls after the first ball is drawn, for example.
( Ugi , it's a game of give and cake, Tue 26 Apr 2011, 17:04, closed)

But but but - when the wrong choice is taken away, you're left with 50/50 chance either way
How does switching help?

No actually, don't bother, I know I'm wrong and this is just one of those things I'll never understand. I read that wikipedia page through really slowly and still my brain just won't accept it. It's like 0.9 recurring = 1, people who do maths understand it, and that's good enough for me.
(leviticus no longer likes the cut of your gib on, Wed 27 Apr 2011, 12:56, closed)