Introduction
FA Premier League
UEFA Leagues
Olympic numbers

Euro 2008

UEFA final

No one will deny that shirt numbers should be clearly legible. But how can legiblity be reached? The UEFA has a Kit Regulation for international European football games.
The way in which numbers should be placed on shirts, is described in article 6. The regulation says that numbers should be 'between 25 and 35 cm in height'. Furthermore they must be 'of one single colour' that must be 'noticeably different from and contrast with the colours of the players' kit, or appear on a neutral-coloured patch'. 'To ensure better legibility, they may be surrounded by a border or shadow outline'. Also the regulation states that the numbers should be 'clearly legible to the spectators in the stadium, as well as TV viewers'. (see www.uefa.com for the complete kit regulations). In short, the goal of this regulation is legibility, and the means are measures, contrasting colours, and outlines.

In practice this regulation has a woeful consequence: stripes on shirts are judged to harm legibility in such a way that UEFA forces teams to print numbers on a neutral-coloured patch. In most cases the typical pattern of the shirt is disturbed.

Looking again at the kit regulation, I can't but conclude that one important means for improving legibility is missing: letter shape. As pointed out in the theory section, legibility is effected by for instance the construction and thickness of the figures. In pratice all kind of shapes are allowed by the UEFA, as long as one can see which figure is meant. Sometimes this leads to very strange figures that can only be identified because one knows that it must be a number. When such a number is moving and influenced by the folding of the cloth, legibility diminishes rapidly.

In my opinion patches on striped shirts are often ugly, so they should be avoided (see: stripes).
But still the question remains how to measure overall legibility. I propose to define legibility of shirt numbers as the distance from which one can accurately identify them. In this case the organizing committee of a competition can determine which is the minimal distance (i.e. legibility) that is required. And any football team can easily determine which numbers are needed on their unique shirts to satisfy this condition.

Stripes with a low light-dark contrast barely harm legibility of shirt numbers. Applying a plain patch doesn't really improve legibility and it spoils the shirt design.