I can explain it (at least the way I was told) but I'm not sure I can convince anyone because I'm not convinced myself.Originally Posted by c_323_h
Let's change this from 3 doors to, say, 10.
You pick, say, door 5.
Monty says, "I'll tell you it's not behind door 7. Do you want to make a new choice?" You say no.
On and on it goes until there are two doors left, door 3 and door 5.
It is better to pick door 3 as your final choice.
The reason is simple enough: Your original choice of a door had a 1 in 10 chance of being correct. Your final choice has a 1 in 2 chance of being correct. The odds are with the other door being right.
I don't like it, but that's how it was explained to me.