Yes. You have a 1/3 chance of getting it in the 1st place, and a 1/2 after the 1st door. However, once he asks, that changes everything (aka variable oods). If you say yes, ill change, you'll have a 66% chance of winnning. I'm guessing I'm missing something but wouldn't it be a 50% chance for door 1 or door 2? Onto another Paradox, someone mentioned something similar but this is different: There is a running race between 2 people. Person A gets a head start and when he reaches 100m, Person B can run. But Person B runs 10 times faster than Person A. Now say that they keep running at a constant speed, will Person B ever catch up to Person A? The answer is no, because by the time Person B runs 100m, Person A will be 10m ahead, and when Person B runs those 10m, Person A will be 1m ahead and so on and so on.