I beg to differ, with BO you cant go by coomb size, esp at 12 weeks! They all develope them at different rates. I have 4 BO that are now about 15 weeks old and I posted on here, everyone said all roo's and I thought all roos esp because of the combs, but now three weeks later and they look no more rooish than they did then, noone has crowed, and I dont see any real saddle feathers on anyone PLUS, now the comb has stopped growing it seems. I am seriously starting to believe I have 4 pullets. If it helps, mine looked like the one you're being told "roo" as of 3 weeks ago....and basically still do.