Squad number (association football)
Squad numbers are used in association football to identify and distinguish players that are on the field. Numbers were originally used to also indicate position, with starting players being assigned numbers 1–11, although these numbers often bear little or no significance in the modern game other than the players' favourite numbers and the numbers available. However, numbers 1–11 are often still worn by players of the previously associated position.
As national leagues adopted squad numbers and game tactics evolved over the decades, numbering systems evolved separately in each football scene, and so different countries have different conventions. Still, there are some numbers that are universally agreed upon being used for a particular position, because they are quintessentially associated with that role.
For instance, "1" is frequently used by the starting goalkeeper, as the goalkeeper is the first player in a line-up. It is also the only position on the field that is required to be occupied. "10" is one of the most emblematic squad numbers in football, due to the sheer number of football legends that used the number 10 shirt; playmakers, second strikers and attacking midfielders usually wear this number. "7" is often associated with effective and profitable wingers or second strikers. "9" is usually worn by centre forwards or strikers, who hold the most advanced offensive positions on the pitch, and are often the highest scorers in the team.