I think breeders would have to breed generations upon generations of twin ball pythons to figure that one out. As some breeders are lucky to pair ball pythons that have had twin births in there background to even produce twins. It's really mere luck because what if a breeder sells one of the twins, there's really no way of keeping that kind of record. When 1) they don't sell for more $ because they are twins and 2) it's not likely to happen again. But I too wonder if there is someone working on figuring that out.