X Factor methodology

[Seabird]

I am a mature university student in UK. My current project involves the use of X Factor data from the Thoroughbred database. It would be very helpful if someone could give me an explanation of the provenance, veracity and methodology used to create the single and double copy X factor lines down the female side.

For instance, are they based on a list of single and double copy mares originating from Marianna Haun (or someone else) or do they all emanate back to Eclipse (looking at the database it appears not). I suspect some other method is used but have not been able to infer what it is. I'd appreciate your help.

Thanks
Seabird

[jagger]

I sent you a pm, Seabird, and you may get more response to your thread on the racing forum or even the general forum. Not too many people read the technical library forum.