The orthodox solution to the Monty Hall riddle is incorrect.

My opponent states that I tell you that his argument relies on an assumption that is not implied in the original riddle. This is absolutely correct, as he is making the assumption that the host may have some kind of deceptive agenda. Furthermore, he is the one to insinuate that the host having an agenda here is a definite possibility, This is a good example of argument ad ignorantiam as my opponent is essentially demanding that I prove that the host doesn't have some kind of deceptive agenda. Keep in mind that it is the job of my opponent to prove this possibility since he was the one to bring it up. However, I've already addressed this in round 2 with my poker game analogy (which my opponent has apparently dropped in round 3). To reiterate, in calculating the possibility of receiving an ace of hearts from the card dealer, you do not conclude that it is impossible to determine the answer since the card dealer could have rigged the deck to purposely give you a hand with no aces. Problem solvers do not consider this possibility unless there is evidence to support it. In this problem, there is nothing stated about the host' attitude/behavior that could lead us to accept strategies numbers two, three, and four. What the player knows is that the host gives him the option of changing doors after he has revealed a door with nothing of value behind it. Thus, in the eyes of the player, the percentages are determined as I mentioned in my analysis. Thus, it would be of the player's best interest to switch. As for obligation, again, it is the job of my opponent to show why this is a variable in this debate. He has not done this, thus being the reason as to why dismissing this argument is well warranted. Of course, to pacify my opponent, there is actually strong evidence against the host needing to be deceptive as well as the host not being obligated to switch. Going back to how my opponent attempted to take this from a realistic approach in round 2, it would really make little sense for the host (whom the contestant has randomly met on the street corner) to rely on deception considering that he wouldn't gain anything out of it. After all, in my opponent's wording of the Monty Hall riddle, the contestant doesn't exchange anything of value with the host nor does the host have any ratings to gain since this doesn't occur on television. Thus, deception would be utterly pointless since there would be nothing for the Host to gain. Therefore, going with the idea that the host is obligated to switch is quite logical. Since my opponent has already conceded to my analysis being flawless, switching is hence the best solution even according to his wording of the riddle. Therefore, the pro wins today's debate. Voters: My opponent has failed to show you the evidence needed to take his extra variables into account, dropped my poker game analogy mentioned in round 2, and has conceded to my original analysis of switching being the best solution. I've presented evidence for all of my claims, thus I maintain the stance that the orthodox solution for the Monty Hall riddle is correct. With that said, I thank my opponent for debating with me and hope to debate with him in the future. I also thank the audience for reading. Good night. :D