I think I've mentioned this here before.As I've gotten older I don't have quite the sensation in my hands that I once had.Some times without realizing it I hold my pipe by the shank.If I let a pipe with a round shank get just a bit loose it will flip upside down dumping ashes.It's happened more than once.I don't have this problem with oval shanks.I have five of them.They are becoming my best friends.