Not so Redslo. Most referees and assistants run what is called 'rights'. With each assistant running from the halfway line to the goal line and the referee running diagonally from one corner to the opposite so as to cover the quarters with no assistant. The senior assistant handles the side with the managers and benches. Very occasionally they will switch to the mirror of this, either to try to keep themselves mentally fresh or more usually because if physical reasons such as a muddy touch-line or, as yesterday, sun in the eyes.