The Method of Analogy

Abstract

We have said that a game-playing algorithm often inspects the same thing many times over. A human, having studied a situation once, will in the future draw conclusions by the use of analogy. But, it often happens that seemingly insignificant changes in the position alter the course of the game and lead to substantially different outcomes. Such changes are said to be essential with respect to the contemplated variations. A human decides, well or poorly, whether a position that has been studied differs essentially from one that has not, and accordingly does or does not investigate variations starting from the latter. If we are to devise algorithms that use this method, we must analyze a) the notion of analogous moves (later we shall often use the term ‘the same’ rather than ‘analogous’) and b) the notion of the difference between positions essential for given variations.