No, that's not right. You need to read up on it more as it's clear you haven't truly understood the puzzle. The host knows what's behind the doors so he'll al

No, that's not right. You need to read up on it more as it's clear you haven't truly understood the puzzle. The host knows what's behind the doors so he'll always eliminate a wrong answer. In the opening, you pick one door. That's a 1 in 3 chance of being right. So there's a 2 in 3 chance it's in either of the two remaining doors. He simply eliminates a wrong answer. Thus, 2 out of 3 times you win by switching. You win 1 in 3 times by staying with your original choice.