Monty Hall will change the way you think

Here’s a game to play this evening with your wife or your catamite. It is an incredibly boring game, but it will help you understand the world better than a bunch of Nobel prize-winners and more than 100 mathematical geniuses, who we will come to in good time. Take three cards — an ace and a couple of jokers. Shuffle them up. Lay the cards face down in front of your partner and tell her that if she picks the ace, you’ll give her a bourbon or maybe a garibaldi biscuit. If she picks one of the jokers, however, she gets nowt.

Tell her not to turn over the card of her choice just yet, simply to tap it. When she’s done that, pick up the two other cards. At least one of them will be a joker — reveal this card to your missus and put the other card, undisclosed, back in front of her.