Logical Thought

Do you ever get into a discussion where something seems perfectly obvious to you, but other people in the group can’t see it? I saw a good example of this recently.

I was in a pub with a group of friends when one of them showed us a “card trick”. This trick involved taking an unshuffled pack of cards, cutting it seven times and dealing seven poker hands. Six of the hands are full houses, the dealer decides to change all five cards in his hand and the next five cards deal him a running flush.

I thought the trick looked pretty obvious and I asked my friend to repeat it so I could check my understanding. He started again by cutting the pack seven times. I pointed out that it really didn’t matter how many times you cut the pack and he disagreed saying that it was important to cut it seven times if you were going to deal seven hands.

This lead to a discussion where it became obvious that half of the people around the table didn’t understand that cutting the pack didn’t change the order of the pack at all. We’d given the cards back to the landlord by then so we couldn’t demonstrate, but the rest of us tried hard to persuade them that we were right. Drinks were lined up on the table and “cut” and all sorts of analogies were tried. Finally I think we has some limited success with an analogy of beads on a necklace.

But I was very surprised that something which is so self-evident to me was such a mystery to so many of my friends.