Goalkeeper

Goalkeeper often shortened to keeper or goalie, is one of the major positions of football. It is the most specialised position in the sport. The goalkeeper's primary role is to prevent the opposing team from successfully moving the ball over the defended goal-line (between the posts and under the crossbar). This is accomplished by the goalkeeper moving into the path of the ball and either catching it or directing it away from the vicinity of the goal line. Within the 18 yard box goalkeepers are able to use their hands, making them (outside of throw-ins) the only players on the field able to handle the ball. Goalkeepers perform goal kicks, and also give commands to their defence during corner kicks, direct and indirect free kicks, and marking. Goalkeepers play an important role in directing on field strategy as they have an unrestricted view of the entire pitch giving them a unique perspective on play development.

Goalkeepers are required to remain on the pitch at all times though that does not mean they have to be between the sticks all the time. For example goalkeepers may have to take a penalty kick during a penalty shoot-out or even go for a corner late in the game though it is rare, as it leaves the goal unguarded. If a goalkeeper is hurt or sent off the back-up goalkeeper must take his place, if there isn't a backup, then an outfielder must do so. In the event of a sending off an outfielder too must leave and the other keeper "replaces" him. If both keepers are hurt or sent off and there is no third choice keeper especially at club level, an outfielder (usually a defender) has to take his place and wear the goalkeeper kit. Because goalkeeper is the most important job in football as well as being the most difficult position to master, most teams have the same keeper play in the starting XI every season. For example Petr Čech is currently no.1 at Chelsea while Iker Casillas has been Real Madrid's no.1 for more than 9 years, and the starting goalkeeper for Spain for over a decade. As a result it could be a long time before the back-up keeper has a chance to play. This is one of the main reasons why most goalkeeper on average retire in their forties. The main squad number for a goalkeeper is no.1 but today though this is still common some goalkeepers now wear other squad numbers when in goal. For example: Despite being no.1 at Liverpool, Pepe Reina has worn the no.25 jersey through all his Liverpool career. No.13, especially in Britain, is the common number for the second choice keeper, though others like 12, 16 (a number attributed to hockey), 24, 25, even 30 (a number attributed to ice hockey) are also common.

General play and technique
The goalkeeper position is the most specialised of all positions on the field. Unlike other players, goalkeepers may touch the ball with any part of their body while in their own penalty area. Outside of their penalty area, goalkeepers have the same restrictions as other field players. They are also "protected" from active interference by opponents within their own goal area.

Perhaps the most spectacular move a goalkeeper routinely performs is the extension dive. To execute this manoeuver properly, they push off the ground with the foot nearest to the ball, launching themself into a horizontal position. At this point, the ball may be caught or simply pushed away. In the latter case, a good goalkeeper will attempt to ensure that the rebound cannot be taken by a player on the opposite team, although this is not always possible.

Responsibilities
The tactical responsibilities of goalkeepers include:
 * To keep goal by physically blocking attempted shots with any part of their body. The keeper is permitted to play the ball anywhere on the field, but he may not handle the ball using his hands outside the penalty area.
 * To organise the team's defenders during defensive set pieces such as free kicks and corners. In the case of free kicks, this includes picking the numbers and the organisation of a defensive man "wall". The wall serves to provide a physical barrier to the incoming ball, but some goalkeepers position their wall in a certain position to tempt the kick-taker to a certain type of shot. Occasionally, goalkeepers may opt to dispense with the wall. Some goalkeepers are also entrusted with the responsibility of picking markers while defending at set pieces.
 * To pick out crosses and attempted long passes either by punching them clear or collecting them in flight.

Although goalkeepers have special privileges, including the ability to handle the ball in the penalty area, they are otherwise subject to the same rules as any other player. Due to the increasing importance of crosses and set-pieces that put the ball in the air, the goalkeeper is often the tallest member of the team, and most stand over 6 ft (180 cm) tall in professional competition, with many well-known keepers standing particularly tall at over 6 ft 4 in (193 cm).