Genetic Distance | YDNA Matches

Melanie Mohler

Share with a friend: 

Genetic distance is a key clue for helping you understand what makes a good YDNA match. Read Ginny’s story to learn how the YDNA for Genealogy Course helped her better evaluate YDNA matches and know which ones are worth further attention.

YDNA can be a wonderful tool to help you better understand patrilineal family lines, but knowing what makes a good match is crucial. It’s important to look at the genetic distance with matches.

What is genetic distance?

Genetic distance measures exactly what it sounds like: how close (or distant) you are genetically from your YDNA matches. The closer the distance, with zero being the closest match, the better the match.

The genetic distance between you and your YDNA matches is the most important column in your YDNA match list. The values you’re looking for in that genetic distance column vary by how many markers are being compared between you and your match. Family Tree DNA currently offers YDNA tests at three different levels: 37 markers, 111 markers, and Big Y (700 markers). (If a close match has tested at a higher level, it may be worth upgrading your own test to a higher level.)

Here, Diahan Southard explains a little more about how YDNA works and the genetic distance information you’ll see on your YDNA match list:

Enroll in Our YDNA for Genealogy Course

Evaluating genetic distance for YDNA matches

Going into the YDNA for Genealogy Course, Ginny Fields had two different matches she wanted to work on in the course: her maternal first cousin’s and her husband’s.

Her cousin had a match at 111 markers with the same surname, but there was a genetic distance of 10. That’s not typically very helpful. “My…cousin has a match with someone of the same name whose ancestors are from Scotland and apparently from the same area that [my ancestors], and my cousins’ [ancestors], are from,” Ginny says. “I am now having research done to see if we can nail this down more.”

Looking at her husband’s YDNA results, Ginny initially thought that he did not have any good matches, either. Her husband had a match at the 37 marker with a distance of three, but the surnames were different. It was through the YDNA for Genealogy Course that she learned that a distance of three at 37 and 67 markers is viable to work with.

After taking our YDNA for Genealogy Course, Ginny then did the genealogy to learn more about her husband’s match. She found that his match’s ancestors were connected to him through a marriage of her husband’s 2x great-granduncle (the brother of his 2x great-grandmother). Interestingly, the two families also lived in close proximity to one another. Ginny’s husband could not have inherited YDNA from his 2x great-grandmother (remember, YDNA is only inherited from genetic males), suggesting this was a secondary relationship he shared with his match.

Ginny is still working through the mystery of exactly how her husband and his match are related. Now, her next step will be to contact the son of her husband’s match to ask if he will upgrade his father’s test to see if the match “holds up” when they compare additional genetic markers.

“I probably would not have explored this match without taking the YDNA class,” she says.

Our YDNA for Genealogy Course covers YDNA matching, with topics including your YDNA match list, YDNA matches with no shared surname, next steps for YDNA matching, and more! This unique course gives you insight into little-understood aspects of YDNA testing and can empower you to unlock the answers already waiting in your relatives’ YDNA.

Enroll in Our YDNA for Genealogy Course


Get More DNA Inspiration

Our free monthly newsletter delivers more great articles right to you.


  1. Daniela-Monica Împușcătoiu

    My father Ioniță Împușcătoiu is dead from 22 february 1994.
    I couldn’t participate to an YDNA analyse.
    Thank you very much for your amability!

    • Diahan Southard

      I’m so sorry to hear that. If you have a brother, or have an uncle on your father’s side then another option is to have one of them test!

  2. pablo the dreamer

    Wish I could nail it down where I saw diferent statements about what FamilyTreeDNA considers a Y-DNA match: GD 10, and (GD?) 40.

    Are they maybe counting STR apples vs SNP oranges? ;>)

    • Diahan Southard

      Depending on which YDNA test you’ve taken (37 vs 111 vs Big Y 700) there are different criteria for who is considered a YDNA match or not, but yes, it does come down to similarities (or differences) in SNPs and STRs, which are both different ways to track how DNA changes over time.

      • William Dodge

        I am trying to resolve unknown GGF. I have lots of matches from multiple 2-3rd cousins. I even have a possible candidate. I’m not sure what training is right for me? I am more experienced than a novice but woefully behind in using tools to break down walls. What do you recommend?

        • Diahan Southard

          Hi! Thanks so much for your message. You have come to the right place, we have all the tools you need to discover your ancestors using DNA. Do you have a copy of our book or ebook? That is what I would recommend for you, it’ll teach you the steps to take to use those matches to find/ confirm who your great grandfather is.

  3. Carol Friesen

    I have a family brick wall that is associated with my gg grandfather, we know who gg grandmother was.
    Great grandfather was an only child as his mother died when he was just over 1 year old 1870’s, when she died, he went to live with his aunts on his mother’s side.
    Great grandfather had 4 children, one being my grandfather.
    My grandfather only had 1 child my dad… who has now passed but my brother is still alive.
    Do you think this test will help us figure out who he was, all we have is a name.
    Thank you for your time

  4. Steve Marsh

    Greetings Diahann, I have a brick wall on my great-grandfather’s line (my mom’s father’s father). My mom had only one cousin on her paternal line, a male. I had been communicating with a DNA match to my mom and I, and fortunately, we were able to talk this kind cousin into taking a 67-marker Y-DNA test. The results showed one person who was a genetic distance of 1, and wouldn’t you know it, that person is the DNA match to my mom and I. And, her father, who is the person she had tested, shared the same sir name as my mom and my mom’s cousin. Unfortunately, I am stuck with these results not knowing what can be derived from this result. Do you have any ideas or direction where to take this?

    • Diahan Southard

      Great job on everything you’ve discovered so far! That is exciting headway. Your next step would be to figure out how this YDNA match is related to you. From your YDNA results it sounds like this person is related through your mom’s paternal line, which is great since that’s the line you are wanting to learn more about. It’s even better that you also already have their match information with the autosomal DNA test too. This article will give you a tutorial on how you can narrow down your relationship to your match:

  5. Marion

    I’m “still” confused as I try to determine a Best Mystery Match.

    My husband is tested at the 67 marker level.
    At 67 markers: 4 matches (2 – 6 steps, 2 – 7 steps)
    At 37 markers: 7 matches (1 – exact [son], 1 – 2 steps, [same person as 7 step
    match at 67], 2 – 3 steps [different people], 3 – 4 steps)

    Expected area (Ireland/Scotland), no expected Surnames

    My question is … can I consider the 37 marker 2 step match be be a BMM

    • Diahan Southard

      We consider a best mystery match at 37 markers to be anyone with a genetic distance of 3 or less, so that two step match at 37 would be a great best mystery match! Our YDNA Course also has great instruction on how to find and use your Best Mystery matches.

      • Paula

        Regarding Best Match analysis ( no shared surnames) for Big Y700:

        Y111 – 22 matches (GD1-2 matches, GD3-1, GD4-5, GD5-2) all tested at Y111 or higher
        Y67 – 43 matches (GD1-5 matches, these tested at Y111 and higher, GD2-8 matches, one at Y700,
        three at Y111 and 4 at Y67, GD3-4 one at Y700 and two at Y111 and one at Y67)
        Y37 – 68 matches (GD1-1 tested at Y700, one at Y111, GD3 – 1 tested at Y700)

        Which of these are Best Matches?

        Profile common or rare?


        • Diahan Southard

          Hi Paula! Your best matches will be the ones who have the lowest genetic distance AND have extensive trees. So I would start with your Y111 matches at the lowest genetic distance and start there to see who has helpful information on their tree. Our YDNA class teaches more about this.


Submit a Comment

Your email address will not be published. Required fields are marked *

Send this to a friend