The best easy to understand rule I have seen is provided by Professor Richard Anderson who literally wrote the book on population analysis.

From an archived thread :

For LMB

This is what is suggested by Dick Anderson - the Prof who wrote the book on PSD.

Keep taking <12 in bass until the number 8-12 equals number 12-15. Ideal pond structure is 40% 8-12, 40% 12-15 and 20% 15+

This assumes good fish condition.

Another suggestion is take out all the fish in poor condition in all size groups. Note the size group that is stunted will have a much higher % of fish in poor condition.

These are all correlated to the concept of RW mgt.

Here are 3 archive links with a ton of info on the subject.

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=255372#Post255372

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=255359

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92492#Post92492

If the only method of removal is hook and line then you need to consider the catchibility issue which underlies your question about genetics.