For whatever reason, I've always had better success training females. I've had my share of males too, but they seemed a bit more stubborn than the females. It might be also, that the males didn't respond as well as the females to my training methods.
It has just been my experience that females are easier to work with for obedience training. Don't ask me why.
Bear, Anna, Molly, Ossie, and The Countess Lisl von Schlaf
An Unhappy German is a Sour Kraut!