Back to the original question.. the analysis of Don is flawed in that he gives equal probabilities to all four situations. However, the two situations A both have a chance of one in six, while the situations B and C both have a chance of one in three.

In bridge there is a "Principle of Restricted Choice" that says something about where to expect a court card if the adjacent court card has already been played by the opponents. This principle is based on the same logic as the Monty Haul problem. A friend of mine, an avid bridge player, follows that principle almost blind. However, when she was confronted with the Monty Haul problem she stayed adamant that the chances were 50%, even when everybody was explaining to her that she was wrong.

Whymme