You're planning to write to me about the Monty Hall Problem, aren't you. That's why you've clicked onto this page. I can see it in your mad, swivelling eyes. Well, don't. Please. I get many letters explaining, at great length, why I've got it wrong . I've finally given up answering them. Life is just too short. The Monty Hall Problem is famous precisely because the correct answer is so infuriatingly counter-intuitive. The irony is that if you play the game (all you need is three squares on a piece of paper, a pencilled cross and a dice) it becomes rapidly obvious that the 'change' tactic increases your probability of finding a car. But there are many very intelligent people who believe that thinking about something is superior to doing it...