Therefore, it may seem pointless to search for the “theory of games”. Meanwhile, reflections lead the individual to attempts to abstract the data, which helps to focus on the essence of the problem. Often one has to choose between elements of many probabilities, the outcomes of which are known beforehand. This is the case of “open” games, such as, for instance, a game of checkers or chess, where the results of moving every chess piece is exactly known. But the player can be not aware of all data of the situation. This is the case of playing cards, which is based on supposition and insufficient information.

Therefore, here one has to choose out of many situations, the outcome of which is not completely known. In this case we are to create hypotheses of probable outcomes. Choice in this situation, introduces us to a new coil of probabilities. Such a game moves from one probability to another. By making possible suppositions, we can calculate compound probabilities from simpler ones according to the formula of conditional probabilities.