It uses an improved positioning that selects the position that minimizes the the largest portion of unobstructed goal area. As with CMUnited '97, when the ball is moving fast the goalie moves to the ball's predicted point using the estimate of the ball's velocity. Stop our opponents from scoring. Don't endanger our own goal. To achieve these ends three behaviors were implemented for the defender.
Clearing tries to push the ball to the other half of the field.
The last behavior, annoying , is somewhat similar to the goalkeeping behavior except the robot tries to position itself between the ball and the opponent nearest to it. Blocking the goal. Clearing the ball. Selecting which of these behaviors is used is very important to the effectiveness of the defender. For example, clearing the ball when it's close to our own goal can often lead to scoring in our own goal.