In the multi-agent systems, even if each agent behaves selfish or cooperative, its behavior influences the other agents' behaviors and their behaviors influence its behavior cyclically. Thereore a certain information about the relative position of each agent among all the agents may be able to be extracted only from its behavior. If this information can be extracted, each agent has the possibility to improve its efficiency only by seeing its own behavior without knowing about the information of the other agents. In this paper, we verified this hypothesis by using the competitive multi-agent simulation environment named Minority Game, and confirmed that each agent's performance gain was actually possible. This analytical technique may be especially useful for massively multi-agent systems.