[lendaddy]

One way of looking at it is when you initially pick one of the three doors you have a one in three chance of having the car. But the remaining two doors (lets call them Monty's doors) have a two in three chance that one of them contains the car. Obviously Monty will remove one option by revealing that goat but now you have one door from a group that had one in thee odds and Monty has one door from a group that had two in three odds. It's obvious that Monty's dorr is the better choice.

Maybe I'm a little slow today though but why does it matter if Monty knows which door has the car? If he forgets and gets lucky by still revealing a goat, are you not still being offered the only remaining door from the two in three group for one from the one in three group?