Done Hatching!

We incubated 14 eggs. The book said to expect a 50% hatch rate. 10 of our eggs hatched, there were six dark and 4 light chicks. The book also said that the hatching would be done in 24 hours, ours straggled along for 72 hours. In the name of science we opened the other eggs, three looked just like breakfast eggs so were apparently unfertilized, the fourth died sometime during development. All were growing nicely for a couple of weeks until a rat got one of the dark ones. I covered their brooder and they are feathering out nicely now. What remains to be seen is how many are pullets and how many are cockerals. According to an old wives tale that I read about we incubated the roundest eggs. Supposedly, the elongated eggs will be roosters. This doesn't seem to have any root in science but perhaps I'm not thinking about it correctly. Or perhaps it is indeed just an old wives tale.