In 1990, Marilyn vos Savant correctly answered a probability puzzle in her column for Parade Magazine. And then, the world called her an idiot.

I still remember the chaos caused by the Monty Hall problem in our high school math class. Here's my explanation for how it works:

  • Your first choice could either be a car or a goat.
    1. If you picked the car, you will win the car by not changing your guess.
    2. If you picked a goat, the host will reveal the second goat. The last door left will be the car, so you are guaranteed to win if you change your guess.
  • You have two possible strategies to win the car:
    1. Try to pick the car on your first guess, and don't change the guess.
    2. Try to pick a goat on your first guess, and change the guess after the host opens another door.
  • The second strategy is better, since picking a goat is twice as easy as picking the car.

The best strategy is to try to pick a goat in round 1. Once the host has revealed the second goat, you are guaranteed the car by switching doors.