[dennisw]

A very smart Japanese man once told me that.
Husband stronger you get more girls
Wife stronger you get more boys

[AnAmericanMother]

That sounds on a par with the Drano and the wedding-ring-on-a-chain test.

My OB/GYN told me that Y sperm swim more slowly than X sperm. But the chances are still 50/50 on every conception.

My father in law was the toughest, strongest man you would ever care to meet. Bird colonel in the Air Force, stood no nonsense from anybody. His wife was a NJ farm girl, no pushover but definitely a traditional bride. All boys.

My dad is an easygoing guy, the sort of fellow everyone likes, not much of a disciplinarian ever (but beware the wrath of a patient man). My mom is a take charge gal, dad says, "If she'd been Allied Commanding General, World War II would have been over in six weeks." All girls.

[ThePanFromJapan]

You forgot the last part of that:

Both strong, you get twins or triplets.