Watching the 2014 World Cup, I've seen that almost all nations print the players' names in capital letters on the back of their jerseys*. Why do they do this? Considering that humans read sentence case text better than they read all caps, it seems illogical to typeset the names in this manner.
Furthermore, the all-caps pattern is not just restricted to football (soccer). Every league in the NFL as far as I am aware, sets players' names in all caps.
What is the rationale behind this? Is it that all caps reduces white space and actually makes it easier for referees to read players' names, or is it something of a legacy that started years ago?
*Italy is an exception, they print names in all lowercase