i agree far too many variables , some familys mature quicker than others, (sprint pigeons) you could find these quicker than (distance pigeons ), as some distance birds dont mature/show anything till there maybe 2 or 3 years old, i have birds that have done absolutely nothing till they went to the distance they were bred for, then i had a bird that won from 60miles 1st club, 1st race then won the last race from clermont in france 543 miles 1st club 1st fed only two in race time , in same season, so all birds are different , so its trial and error mate sorry