I'm just wondering, why not give the service judge power to overrule line calls? A lot of times in international tournaments, it seems like the umpire can't make a correction because they can't see a clear error, being on the other side of the court..so why not let the service judge have some power in that area?
Because they are a "service" judge and their main focus are on serves only, while line judges are for lines. Plus they both sit at different angles so they see it differently. If we're talking about clear obvious missed line calls, then they can make a secret hand signal to the umpire usually.
