Pruning

 

Have you ever written a program to play chess? Neither have I, but I knew someone who did, and he explained the logic of it to me—and it’s the same logic we humans use to solve complex problems. Back in the days when computers weren’t powerful enough to analyze all possible moves in a chess game, a chess-playing program worked something like this: Once the program gets past any standard openings, it begins to employ a point system applied to all current moves. We can conceptualize the game as a tree, each branch containing a set of possible moves with each move possessing another branch, and so on. The software will search a certain number of layers deep, determine which move has the best score, and then make that move. This technique of looking only so deep in the tree is called pruning. We cut the searching off at some point and look no further. Humans examine steps in a puzzle or hunt in a similar fashion. 

A common error I see is that treasure hunters tend to accept the obvious interpretation and look no further. We must examine many possible interpretations even when a simple explanation presents itself. Remember, a good puzzle will not be obvious. With these puzzles the obvious answer is always the wrong one, just part of the subterfuge, a trap for us to fall into. The correct answer will always be interesting and unexpected.