I always try to go by the booty and the leg feathers! If there's a split at the top of the booty? It's usually a roo! And if the back ankle feathers are long at about a day or two of age? It's a roo! If the front feathers above their eyes are square looking? It's a roo! I've had very few fool me thru the years! The chick in the upper right corner of this page is what I'd consider a roo! It's got the bushy/long leg feathers and the squared off feathers above it's eyes!
Okay Fancy! Ik Ik Ik It's a 50/50 chance either way!
TC