you are unsure as to whether your opponent's shot was in or out ask
for the views of the other players.
you and your partner take responsibility for monitoring and reporting
line calls on your own side of the court, unless your partners vision
is compromised and the call is an obvious one.
a player serves the ball fast it can be difficult for the person returning
the serve to see whether the serve was in or not, particularly if it
is on or close to a line. Therefore, your partner - the non receiver
should make a call as to whether the ball was long or not.
making a line call a player should not enlist the aid of a spectator
or someone playing on an adjacent court.
is both the obligation and prerogative of players to call all shots
landing on, or aimed at, their side of the net, to help your opponents
make calls when the opponent requests it, and to call against yourself
any ball that you clearly see is out on your opponent's side of the
players being human, they will all make mistakes, but they should do
everything they can to minimize these mistakes, including helping an
opponent. No player should question an opponent's call unless asked.
When an opponent's opinion has been requested and he has given a positive
opinion it must be accepted; if neither player has an opinion the ball
is considered good. Obviously, aid from an opponent is available only
on a call that terminates a point. In accordance with the laws of parallax,
the opinion of a player looking down a line is much more likely to be
accurate than that of a player looking across a line. When you are looking
across a line don't call a ball out unless you can clearly see part
of the court between where the ball hit and the line. This means if
you are half a court or so away and a ball lands within two inches of
a line it is almost impossible for you to call it with accuracy. A player
who stands on one base line and questions a call concerning a ball that
landed near the other base line is probably being ridiculous.