DUAL mechanics, anyone?

[KYRef2]

Originally posted by ejstuart
What's the advantage to that? Someone always needs to be even with the second to last defender, and close enough to the touchline to determine fouls.

As I see it, the advantage is that if play is on the far side of the field, the lead official (former AR) can cheat to the center and keep a closer eye on the boxed play - instead of hoping to see something from 45 yards away, over a crown in the middle of the field. If nothing else, it gives the lead official a good view of play and the entire endline to determine corner kicks and goal kicks.