Random choice would be optimal if the host didn't know the location of the car. If the host is blind & car wasn't revealed already, there's 1/2 chance. If the h

Random choice would be optimal if the host didn't know the location of the car. If the host is blind & car wasn't revealed already, there's 1/2 chance. If the host knows & the car is hidden, then the remaining door has 2/3 chance