From my new book “The Missing Rudiments - ”The current modern majority opinion is that, since they can’t both be and are not the same thing, a drag has double stroke grace notes and most ruffs have single stroke grace notes. I agree with that majority in keeping it simple but with the caveat that there are other known stickings for ruffs by historically important authors, which are included in this book. So,“ruff is ruff, drag is drag, and never the twain shall meet.