As mentioned several times, a limiting factor in finding Common Ancestors with your atDNA matches is unknown ancestors. Both you and your match have to have the same Ancestor(s) in your Trees to determine a match. When making up your Ancestry - to share for atDNA matching only - I say: Throw in the Kitchen Sink! Folks tend to include only those ancestors in their Tree that can be proved with documentation, and without a doubt. I think you should include every possibility, every alternative, every hunch, every neighbor (in the case of missing maiden names), everyone from online files like Ancestry, IGI, DAR, etc, etc. - you get the idea. If it's a possibility include it. Remember, you and your match are both looking through long lists for just one Ancestor/couple that matches. The match could equally be any one of your ancestors, and any one of your match's. The match could be beyond your brick walls - this process may fill in some of these voids. You want your list to include as many possibilities as possible. It doesn't make much difference to the match - just a little more to scan. The same is true if you're using GEDmatch. As always I suggest adding Patriarch (or Matriarch) names/dates/places to the surnames to make them more readily recognized. When/if you determine the Common Ancestor is one of your Kitchen-Sink ancestors, you then compare notes with your match. You focus your genealogy skills on this specific Ancestor and decide if it's real or not. You may also find some clues in the atDNA info... The farther you can stretch your Ancestry - only for atDNA matching - the more Common Ancestors you'll find. Then decide whether to keep this possibility in your Tree. Jim - Sent from my iPhone - FaceTime!