Couple years ago Etneo posted on Gardenweb how to identify a Breba crop.
http://forums.gardenweb.com/forums/load/fig/msg0820560215230.html
he said, " a Breba forms below the leaf while main crop is above the leaf.
Did anyone notice that?

If I understand what he is saying...

Since brebas are formed on last years growth/wood, and the tree will lose its leaves when it goes dormant, and assuming (I think correctly) that any new leaves will only be formed on new growth/wood...then any figs appearing below the new leaves must be on last years growth/wood, and therefore are breba figs. If the fig appears in amongst the new leaves, it is a main crop fig, having formed on the new growth/wood, which produces leaves and main crop figs.

What Jon is saying implies that the main crop is produced on the new year growth only, and not on any older part of a branch. Is this correct that the main crop never grows on previous years woods behind the new year growth? I do not have personal experience yet so knowing one way or another will help in pruning ideas.

If you want breba figs (assuming your varierty has a breba crop), you must leave the previous years wood. If you don't care about breba figs (like me) then you can prune a 10 foot tree to 18" with no problems.

Plainly, being consistent with my good old believes:
Breba (fig fruit) grows on LAST year fig wood;
Main Crop  ( 2nd fig fruit ) grows on THIS  (current summer) fig twigs...
As simple as that...
George (NJ).