Football is played in a series of rules, officially called rules. This sport is practiced with a spherical ball (leather or other material with a circumference greater than 70 cm and not less than 68
cm, and weighing not more than 450 g and not less than 410 g at the beginning of the game), where two teams of eleven players each (ten players "field" and a goalie) compete to fit it in the
opponents' goal, marking a goal. The team has scored more goals late in the game is the winner, if both teams do not score or make the same number of goals then is declared a draw. There
may be exceptions to this rule, see below Duration and outcome.
The main rule is that players, except goalkeepers, may not intentiona lly touch the ball with their arms or hands during the game, but must use their hands for the throw-ins.
In a typical game, players try to get the ball to the opponents' goal, which is called a goal through individual control of it, known as dribble, or pass to colleagues or shots on goal, which is
protected by a goalkeeper. The opposing players try to regain control of the ball by intercepting passes or by taking the ball to the player who has, however, physical contact is limited. The
game is free flowing football, and stops only when the ball leaves the field or when the referee decides he must stop. After each pause, restart the game with a specific play. At the end of the
match, the referee compensates for the total time in minutes that the game was suspended at different times.
At the professional level, most matches are marked only a few goals. For example, during the 2006/07 season in the Primera Division of Spain, the Spanish football league, has set an average
of 2.48 goals per game.
The rules do not specify any other position players other than the goalkeeper, but over time have developed a number of positions in the rest of the field. Broadly speaking, there are three main
categories: strikers, whose main task is to score goals, defenders, located near his goal, who try to stop the rival forwards, and midfielders, who handle the ball between the previous positions .
These players are referred to as outfield players, to distinguish the goalkeeper. In turn, these positions are divided into t he sides of the field in which players play most of the time. For example
midfielders may be right, center and left. The ten outfield players may be distributed in any combination: for example, may be four defenders, four midfielders and two forwards, or three
defenders, four midfielders and three forwards, and the number of players in each position determines the style of team play : more forwards and fewer defenders creates a more aggressive
and offensive game, while the opposite will generate a slow and defensive game. Although players usually maintained for most of the time in one position, there are few restrictions on their
movement in the field. The outline of the players on the pitch is called the team's formation, and this, along with the tactics, the coach's job.