For me, must points to select when buying a so called "BD" are:
1. 3 complete white spot rings at outer disc.
3 completed rings inclusive of a tiny spots ring just at the edge of the disc. In total, there are about 6 or more white ring spots on the disc plate.
2. White spots should be [white - as white as possible], [round - if possible] and [big - except for the initial 3 rings], try to avoid those yellowish spots unless you are convinced that they can be turned white.
3. Many tiny spots on both eyes' lips.
4. No pink partner foot print on the disc.
5. Disc plate must be charcoal black, try to avoid those greyish base.
6. Under belly spots - some may not have. For me, importantly must have item 1,2,3 & 5.
7. Of course, the short flat tail.
Who can confirm that in the wild, rays do not cross mate?
To me, BD is also P13 Leo. In captive breeding, BD and good quality leo and with few generations may also produce better quality P13. What would you name this "pup" if they look same or better than a pure BD? Subjective and to be discussed??
What if we have BD and P12?
Will we be able to get "Pure Whitish Spots" and "Charcoal black disc" when P12 gene has yellowish spots and greyish disc? Perhaps, after few generations?
Finally when you are buying a bd, you judge the look of the so called BD, very nice pay more, average pay less, have doubt don't buy. How to tell a pure BD after so many generations of selective breeding. Which breeders will not want to create new higher quality species for higher price?
Out of topic? Sorry, i talk to much.
Regards