[bossref]

Trusting your partner has nothing to do
with it!Getting the call right does!
Maybe where you ref ALL partners are PERFECT.
There are many times when you've got to let him
have it all:Player driving in to score one on one
and partner not screened out, Action in the midcourt
area, etc etc.
However, in a pre-game with 2 experienced partners
it is best to say: "Hey don't worry about our areas.
If something important happens and you see it for sure,
make the call! That way we both look good."
The players and coaches don't care about whose area
it is. They care about getting the right call.
Why don't you try to think about the game more than
you think about your partner's primary area.
Sometimes partners are screened out.
Sometimes they have a brain fart.
Sometimes they don't bring their A game.
Sometimes action occurs in a "gray area"
or a "shared area. Fullcourt press with a bang
bang play near halfcourt.
Don't go "reaching" into your partner's area
on a regular basis. Respect his area under normal circumstances. But don't be an idiot and ignore
what's really important because you want to
only make calls in your primary area.
Your comment about why do I need a partner if I'm
going to call everything, shows your lack of experience.
I'm not going to call everything, but I will always
protect the shooter and I will always make whatever
call is necessary when a game is on the line,
especially if my partner is sucking on his whistle.
Maybe that's why the players and coaches respect me.
Try dialoging with your partners before the game.
Let them know that you want to cooperate, that
you will be there for "help" if needed, and will only
make calls in their area if you KNOW for SURE
that the call was the right one and absolutely necessary.