You need a new trainer. ;)

(Or at least you need to clarify this with him/her)

When would you ever call a backcourt violation without the ball being in the frontcourt first? :D

This is how I pregame it too in 3-person, although with some people, it never happens. I will be the C and have an on-ball defender, and the Lead will be standing there with his hands in his pockets.

Thus my 3-person mini-rant the other day...

We should not deal in absolutes in officiating.

As a general rule, the times where the C would have a backcourt violation are few, but there are several instances where it would be the case. What happens on a transition play where a player catches over halfcourt, attains frontcourt status and then dribbles backward? The trail will not be in position to determine a BC violation.

The second, is a flatout call of assistance. If you are 110% sure the trail misses it then you can get it. I caution you that if you have not seen the whole play often there could be a tip ball and so you really need to make sure it is a high-certainty call that everyone in the gym sees besides your partner.