>>713714095
Maybe my version will help you understand.
When you first make a choice, there are 3 possible outcomes.
>Goat 1
>Goat 2
>Car
As you imagined, the chance of winning is 1/3.
Now, the game show host revealed one of the goats., what do you do?
>If you selected Goat 1 and you switch, you win
>If you selected Goat 2 and you switch, you win
>If you selected the car, you lose
Open the door effectively flips the chance of winning and losing. Because your loss becomes a win, and your win becomes a loss. And your chance of losing originally was higher.