In our multi-agent approach, the player positions itself flexibly such that it anticipates that it will be useful to the team, either offensively or defensively.
One way in which agents can use the position flexibility is to react exclusively to the ball's position. When reacting to the ball's position, the agent moves to a location within its range that minimizes its distance to the ball. This was the mechanism used successfully by the CMUnited-97 teams [17].
The flexible roles defined in the CMUnited-97 software were an improvement over the concept of rigid roles. Rather than associating fixed coordinates with each position, an agent filling a particular role was given a range of coordinates in which it could position itself. Based on the ball's position on the field, the agent would position itself so as to increase the likelihood of being useful to the team in the future.
However, by taking into account the positions of other agents as well as that of the ball, an even more informed positioning decision can be made. The idea of strategic position by attraction and repulsion (SPAR) is one of the novel contributions of the CMUnited-98 software.