Volleyball Rules

Player regulations
On-court positions
Players usually do not need to master all six techniques: serve, first pass (receive serve), second pass (lift, dribble), spike, block, save, but usually specialize in one or more of them according to the team's tactics. The most common position allocation includes three positions: attacker (divided into main attacker and secondary attacker), second setter, and libero (a player who specializes in defense). In order to effectively block the opponent's attack and bounce the ball back to the opponent's court at a steep angle and high speed before the opponent has enough reaction time, generally tall players with good jumping ability serve as attackers.
Main attacker: The main attacker is the player who attacks near the marker. Since most balls passed to the main attack position are high balls, the main attacker often uses a long run-up, sometimes even starting from the sideline. In the offense, the main attacker usually relies on powerful smashes to score, but sometimes it is also required to use diagonal runs and fast breaks to disrupt the opponent's defense. The main attacker also needs to master the first pass technique because they are usually the second first pass point besides the libero when the opponent serves. Right-handed main attackers are best suited to attack at position 4 (front row left), whereas left-handed main attackers are best suited to attack at position 2 (front row right).
Secondary attackers: Secondary attackers are players who often play fast breaks near the setter. Secondary attackers specialize in blocking, because they must block fast breaks from the opponent's secondary attackers and need to move quickly from the center to both sides to organize double blocks. Secondary attackers are usually the tallest players on the team and are required to have good defensive skills.
Second setter: The setter's responsibility is to organize the team's offense. They are responsible for sending the ball to the position that is most suitable for the attacker to spike during the second pass. The setter must be able to combine with the spiking player to create multiple changes to disrupt the opponent's defense. Fast movement and accurate passing are essential qualities for a setter. A good ball-lifter can string together the offensive of the whole team, and must have a good understanding of the characteristics and habits of each attacker on the team. In addition, he must keep a clear mind and thinking during the game. In addition, the setter must also play the role of an attacker at certain times. Therefore, in addition to practicing ball-lifting skills, the setter must also have some long ball attacking ability. Therefore, the training and development of an excellent setter is also quite hard. Therefore, a good setter is the soul of the whole team.
Libero: The libero is a full-time defensive player who is responsible for receiving serves and spiking (saving the ball). Usually the libero has the fastest reaction speed and the best first pass technique in the team. Since the libero does not need to attack or defend in front of the net (the rules do not allow it), it can be a short player with good first pass technique. Players designated as liberos in the game cannot play other positions. The number of substitutions for the libero is unlimited, but there must be a dead ball between two substitutions, and the libero can only be replaced by the person being replaced. The substitution time must be made before the referee blows the whistle to signal the serve. In particular, the libero can replace different players twice in the same game. Before the start of each game, the libero cannot enter the game first and must wait for the second referee to check the starting player before he can replace him.