If you started with 4 doors, where 3 of them had goats, wouldn't you have a 1/4 chance of picking the car the first time and a 1/3 chance of picking the car the second time?
1/4 chance if you keep your original door, 3/4 chance if you switch (assuming the host opens two doors to show goats). If the host opened one door (so you have your original door and two other doors to pick from) then it's a 3/8 chance if you switch, if that's what you're asking.
