When is the best time to call someone through?

[grumpyjock]

I think most people get called through when the group in front has lost a ball off a tee shot.
Of course they didn't hit a provisional so are determined to find it.
The problem then is if you call the group behind through, you have to then wait an age for them to tee off, then walk down to their drives then hit their seconds then chip on and hole out before you can play the ball you found 5 seconds after you called the group through.
And as we all know, after you call someone through, you aren't suppossed to play another shot until the group you call through have played and are out of range.
No wonder people don't want to call groups through.

Agreed but do not pick up a ball thinking its been lost, and then have the group called through chuntering about losing a ruddy ball.