Thanks Bill!
My "100%" solution is to create a micro grow-out pond that is easy to seine.
Follow your advice above and put in the single-sex fish and some appropriate spawning habitat. If there are no YOY the following year, then I probably managed to correctly sex ID the fish!
Move those fish to their final destination pond, and then rinse and repeat.
If I make the system sufficiently "idiot proof", then it just might work for me!
