It's helpful but not ironclad. Just this week I learned my greatgreatgrandfather, who I was sure was named Patrick because his son and daughter named their first sons Patrick, was actually John. His daughter named her third son (my grandfather) John and his son named none of his sons John. But the rule was probably followed more often than not. Diane PS: Did any of your Ballybay Duffys or Hands marry Johnstons?