You get a coin, close your eyes, turn around until you are dizzy then toss the coin. Do this 100 times per egg. If heads out number tails there is a 51.3 percent chance it is male. Double check with one of those magnet things. If the results are inconsistent repeat it 1000 times (for statistical significance) and by now your eggs should be hatched and old enough to sex but you can’t remember which chicken came from which egg and just throw up your hands in dismay and enjoy your chickens (joke!).
Seriously though (not really!) whatever you want to hatch, you’ll select eggs of 84 percent of the other sex. This is a verifiable scientific fact discovered and named after Dr. Murphy.
I’ll finally be serious, like guaranteed homeopathic cures for cancer, if someone had a halfway decent way to sex eggs, big chicken (or big pharma) would be all over it. To hobbyists it is annoying, to big chicken it would be worth millions!