I'll give it a shot. When you choose door 1, you have a 2/3 chance of goat. That means that 2/3 of the time, Monty doesn't get to choose a door (You're on one

I'll give it a shot. When you choose door 1, you have a 2/3 chance of goat. That means that 2/3 of the time, Monty doesn't get to choose a door (You're on one goat, he can only reveal the other goat). So he only has one choice, the other goat. Since 2/3 of the time he's forced to avoid the car, that means that 2/3 of the time you will switch to the car.