If the dog is for myself - I just hold on to the pup or pups for myself for a good while that my gut feeling says to hold on to them. I may keep holding them till they are a year or more. Usually putting them in as puppy classes to see how they do. After you have been breeding awhile you just get a feeling - and keep watching is the best you can do with this breed. Of course you have others evaluate them for you too - someone that really knows the standard (an expert in showing). Soonest - around 8 weeks 12 weeks I think maybe.... but no sure thing. Our breed is one of The hardest to determine. This is one reason show prospects must be held on to for so long. I am still holding my breath until the dog has both their majors and half way to finishing. It's tough!