The aim of the present study was to clarify some aspects of a coach's ability to understand the situation in a team ball game. As an illustrative example, a handball match directed by one of the authors (a men's university handball team coach) trying to create an advanced organized defense tactics in the team was studied, focusing on how the coach understood the match situation at any given time. To analyze the coach's ability, phenomenological transcendentalist reflective analysis was conducted using a questionnaire.<br> 　The team's organized defense tactics were characterized by the flexible use of a zone defense against the opposing team's attackers and an attacking defense that put the attackers under pressure by attempting to gain possession of the ball.<br> 　The study revealed the following points: The coach i) assessed the situation in terms of how the defenders were performing their individual tactical skills against the opposing team's attackers, and ii) tested the tactic he had developed during the match to assess its effectiveness, and to refine it if possible. This approach appeared to govern the way the situation was assessed, and iii) the time was divided into phases in which the functionality of the tactic was maintained at a certain level and phases in which it was maximized, with the use of player substitutions to control that functionality, taking into account the “momentum” of the game. Finally, this allowed the coach to iv) decide to call a team time-out if the applied tactics were not working well, or if appropriate measures could be adopted for dealing with the situation, while still allowing the players to operate independently. The authors believe that these findings will serve as a valuable resource for ball game coaches who need to direct matches.