right, and with their back to the attacker), and also having to jump from the back row when the setter is on the front row. At elite level, until the 1990s several opposite hitters used to be able to also play as middle hitters (e.g. Andrea Zorzi, Andrea Giani), before high specialization curtailed this flexibility in the role. At some levels where substitutions are unlimited, teams will make use of a Defensive Specialist in place of or in addition to a Libero. This position does not have unique rules like the libero position, instead, these players are used to substitute out a poor back row defender using regular substitution rules. A defensive specialist is often used if you have a particularly poor back court defender in right side or left side, but your team is already using a libero to take out your middles. Most often, the situation involves a team using a right side player with a big block who must be subbed out in the back row because they aren't able to effectively play backcourt defence. Similarly, teams might use a Serving Specialist to sub out a poor server. Formations The three standard volleyball formations are known as "4–2", "6–2" and "5–1", which refers to the number of hitters and setters respectively. 4–2 is a basic formation used only in beginners' play, while 5–1 is by far the most common formation in high-level play. 4–2 The 4–2 formation has four hitters and two setters. The setters usually set from the middle front or right front position. The team will, therefore, have two front-row attackers at all times. In the international 4–2, the setters set from the right front position. The international 4–2 translates more easily into other forms of offence. The setters line up opposite each other in the rotation. The typical lineup has two outside hitters. By aligning like positions opposite themselves in the rotation, there will always be one of each position in the front and back rows. After service, the players in the front row move into their assigned positions, so that the setter is always in the middle front. Alternatively, the setter moves into the right front and has both a middle and an outside attacker; the disadvantage here lies in the lack of an offside hitter, allowing one of the other team's blockers to "cheat in" on a middle block. The clear disadvantage