RoboCup is an international scientific initiative to advance the state-of-the-art of intelligent robots. The 2D and 3D simulation leagues in RoboCup Soccer focus on artificial intelligence and team strategy. Several people have proposed numerous models wherein artificial intelligence is used to operate eleven agents of a team. However, most people have constructed an agent model after seeking special knowledge of soccer. Therefore, we construct an algorithm to study decision making of a ball holder using real-coded genetic algorithm.