Generally speaking, I'd keep a pair if they showed something unusual or were just shining examples of what I like. Let me apologize now to my other half for any future holdbacks! lol From the litter I produced in 2000 (my only one so far), I kept a pair. The female was exceptionally light, the only one in the litter like her, and the male showed a lot of pink at birth and even more so after his first shed. For some unknown reason, the male died last year. I didn't discover it immediately (he was always prone to hiding) and didn't bother to attempt to have a necropsy done due to that. The female I kept, however, has always done great.
I'm also still waiting to see if a female (Freckles) that I bred last fall/winter is gravid. At first I figured it didn't take (she shed numerous times and didn't really go off feed). Then my best friend's boa (who was bred at the same time) gave birth to a bunch of slugs and two live babies a couple of weeks ago. It was past when we figured they would give birth (sperm retention maybe? error on our figures?), so now I'm just waiting. *sigh*
My best friend produced her first litter last year and she gave me a pair out of them. The female (Annabelle) is a probably best described as a partial jungle. She has abnormal saddles for 1/3 to 1/2 the lower portion of her body. I also got a male from the same litter who appears normal to breed back to her. A number of the other littermates showed abnormal saddle patterns and one partial reverse stripe was produced as well. Needless to say, we both have high hopes for the holdbacks we both kept.
Raven *counted among the boa addicts* 
