
Y sperm tend to be faster, but have a harder time surviving in the vagina. While x sperm tend to be hardier, but are slower to fertilize the egg. So if the couple has sex a couple days before the woman ovulated the chances are higher for a girl, but if if they have sex the same day the woman ovulates it is more likely to be a boy.
Much like men with longer penises

Y sperm tend to be faster, but have a harder time surviving in the vagina. While x sperm tend to be hardier, but are slower to fertilize the egg. So if the couple has sex a couple days before the woman ovulated the chances are higher for a girl, but if if they have sex the same day the woman ovulates it is more likely to be a boy.
H-how u'll make sure it's a girl tho.. by killing every boy and keep the girl ಠ,_」ಠ?