attacker without the ball first touching the ground; this is called a direct set. The setter will often call "direct" or "indirect" prior to the set, to allow the attacker to adjust his or her approach. Most sets are performed by the setter, however in many situations one of the attackers will be required to set due either to positioning, or the setter having already been forced to hit in defense. A good attacker must also be competent in setting the ball. Attacking A good attacker will be able to hit the ball with high impact (good hits will reach speeds of over 100 km/h), be able to access weaknesses in the positional play of the opponent and have a great repertoire of strokes. The primary attacker is positioned next to the server, who acts as the secondary attacker. The attacker uses the forward spin of a well-placed ball from a set to jump and hit it with full force into the gaps of opposing defenses. Ideally, the attacker must be unpredictable to the opposition, ensuring the direction and speed of the attack can not be predicted by the defense until the hit takes place. As with the server, the attacker has a wide range of possible variations for attack, but the choice and effectiveness of each hit are particularly dependent on the success or failure of his team's ability to set up the attack from defense. For indoor fistball, the dimensions of the court change the approach of the attack, as the run-out section for indoor play is usually very limited due to the close proximity of walls. This fact is exploited by the setter, who will try to place the ball just about the net so that the attacker can hit the ball sharply across the court, restricting the opponents ability to get behind the ball before it hits the wall. In order to stop this occurring, the opponent must attempt to block the ball at the net, similar to volleyball. This has significant effect on the formation and strategy of defending teams. Referees A fistball game is controlled by a referee, who is assisted by two linesmen. The referee has sole decision-making power. He or she makes the final decision on all points or errors. Since the linesmen are relatively far away from the referee, he or she is also responsible for observing the sidelines on his