With long tail fowl you need to pay a lot of attention to the female tail. The old timers will say that you make more progress selecting your hens for sickles and tail length and fullness than on the males. One thing for sure is you can make a determination of genetic potential in the hens tail far sooner than the male side as he takes longer for his tail and sickle feathers to really mature. In addition, a chicken normally has 12 (6 on each side) main tail feathers (not counting mutant sickle feathers). Some chickens you can reasonably count 14 to 16 main tail feathers with feathers numbers 7 and 8 being sometimes questionable depending upon who is counting. At any rate, you can count those main tail feathers and select for more in the future breeders and make progress with tail fulness that way.