Let's say Monty doesn't open any door, but after you've chosen one, he offers the chance to switch to both of the other doors. Pretty clear then that switching

Let's say Monty doesn't open any door, but after you've chosen one, he offers the chance to switch to both of the other doors. Pretty clear then that switching gives you a 2/3 chance of getting the car, and that is essentially the choice Monty is offering.