Passing to keep possession in overloads is hard work for a defending team but if they can win the ball they take control of the game and move to the other half of the pitch
Your players are involved in transitions of play, defending when outnumbered and keeping possession in overloads. Key to defending is anticipating where a pass will go to block movement up the pitch. But in the transition the team will benefit from overloads. Good passing and moving, speed of play and one or two touch adds to development of individual skill.