Distinguishing Intent
I asked Sam how to tell the difference between intentional similarity and accidental similarity. It would be unfair of me not to answer the question myself.
First of all, I must state my belief that it is possible to differentiate purpose from accident. Again, this belief is rooted in my former employment, some of which involved target recognition. A smart bomb needs to be programmed to distinguish a man-made structure (a bridge or an armored vehicle) from a natural feature (a tree or a rock). Algorithms do exist for making the distinction, which I am not at liberty to share.
The game of poker, however, is not subject to security restrictions, so let’s see if you can recognize purpose from accident in a friendly game of poker. The photographs below show four hands dealt during a poker game. The hands were dealt twice. The first time was Deal A, and the second time was Deal B.
In Deal A, West was dealt a flush, North was dealt a full house, East was dealt four-of-a-kind, and I (South) dealt myself a straight flush (the highest hand).
Do you think I dealt those hands from a shuffled deck, or a stacked deck? If you think those hands (which encourage my three opponents to bet large sums of money, only to lose to my straight flush) were honestly dealt from a shuffled deck, I would like to invite you to my high-stakes poker game next Wednesday night.
Now consider Deal B.
Could those cards have been dealt from a shuffled deck? Yes, they could. In fact, they were.
Why might you believe that Deal B came from a shuffled deck, but Deal A came from a stacked deck? Your first response might be, “The odds against Deal A are so small that it could not possibly have happened by chance.” That’s the wrong answer. Yes, the odds against Deal A are very small indeed, but it could possibly have happened by chance. I would not bet on it—but it could happen.
But it isn’t really a question of probability. The probability that those 20 cards in Deal A were dealt in that order is exactly the same as the probability that the 20 cards in Deal B were dealt in that order. Let me say that again a different way to make sure I make myself perfectly clear. Deal A is no less probable than Deal B. If you shuffle a deck and deal out 20 cards, it is just unlikely that those 20 cards will match Deal B as Deal A.
But you were able, instinctively, to know that Deal A came from a stacked deck, and Deal B came from a shuffled deck, even though both hands are equally unlikely. Since probability has nothing to do with it, how were you able to recognize my nefarious purpose in Deal A?
It all comes down to “meaning” or “purpose.” The four hands in Deal A have meaning, and serve a purpose. (Their purpose is to beat a less powerful hand.) Because it has meaning, there is a name for South’s hand in Deal A. It is called “a straight flush”—but there is no name for South’s hand in Deal B because it has no meaning, value, or purpose.