Sherlock Holmes v James Moriarty [Sherlock]
Holmes and Moriarty are sitting in a small room with concrete floors and walls. They are seated opposite each other, with a good ten feet in between. On a small coffee table on the midpoint, there are two glasses of wine - one contains poison [a la "The Princess Bride] Neither of them have immunity, neither of them know which cup contains the poison. They must remain seated for ten minutes, and then go for the wine glasses.
So, they must outhink each other. In ten minutes time, will Sherlock's extreme observation out the poison? Or will James' "criminal consultancy" aid him in identifying the poison?
Is this just going to be fifty/fifty? Or while one man figure it out?