Given all of the individual skills available to the CMUnited-98 clients, it becomes a significant challenge to coordinate the team so that the players are not all trying to do the same thing at the same time. Of course one and only one agent should execute the goaltending behavior. But it is not so clear how to determine when an agent should move towards the ball, when it should defend, when it should dribble, or clear, etc.
If all players act individually -- constantly chase the ball and try to kick towards the opponent goal -- they will all get tired, there will be nowhere to pass, and the opponents will have free reign over most of the field. Building upon the innovations of the CMUnited-97 simulator team [8], the CMUnited-98 team uses several complex coordination mechanisms, including reactive behavior modes, pre-compiled multi-agent plans and strategies, a flexible teamwork structure, a novel anticipatory offensive positioning scheme, and a sophisticated communication paradigm.