I think of stock birds as birds that breed winners not birds that might breed winners and if you have 2 stock pair that breed winners each year you are a lucky man.
I know guys that have 20 to 30 stock pairs and never win a race. theses same birds are 4 to 10 years old. Why are the birds in the stock loft if they do not breed winners? They tell me it is a son of this, a full brother to that, Who gives a xxxx if it is not racing or breeding winners it should be in the bin not the stock loft.