GEDmatch Introduces Automated Tree Matching

GEDmatch has just introduced a great new tool – automated tree matching. You’ll find it under the “Find common ancestors (MRCA) from DNA matches” on the application menu under Tier 1 tools which are available for a $10 monthly subscription. (Yes, you can subscribe month by month.)

gedmatch mrca.png

Of course, you’ll need to have your tree uploaded so that GEDmatch can match ancestors in your tree against ancestors in other people’s trees.

I wrote about how to upload a GEDCOM file, which holds your family tree information, in the article, Download Your Ancestry Tree and Upload It Elsewhere for Added Benefit. Step-by-step instructions for uploading both DNA files and a GEDCOM file to GEDmatch are included in this article.

MRCA (Most Recent Common Ancestors) Search Tool

Clicking on the “Find common ancestors (MRCA) from DNA matches” link takes you to a screen where you’ll enter your kit number.

gedmatch mrca search

The default settings work fine. 10,000 is the maximum number of kits it will compare.

Next, you’ll see the processing screen.

gedmatch mrca results.png

click to enlarge

In my case, of my highest 10,000 matches, only 1036 had associated GEDCOM files. That’s only about 10%. Imagine how much information would be available if everyone uploaded a GEDCOM file.

Of those, I had 136 hits of people where potential common ancestors could be identified in our trees.

When processing is complete, you’ll see a list of your matches complete with your common ancestors. How cool is this!!!

gedmatch mrca matches

click to enlarge

I’ve obscured private information. Looking at this information, column by column:

  • I can click through to my match’s tree by clicking on the green tree icon.
  • The cM column shows the total matching cMs over the threshold of 7. In the case of my first match, that 52.5 cMs is broken into 2 segments of 19.6 and 32.9.
  • The Common Ancestor in Primary GEDCOM is my ancestor.
  • The Descent Path to Primary Kit is how I am descended from that ancestor.
gedmatch descendants.png

click to enlarge

For example, clicking on the 5G in the first row shows me that I’m 7 generations removed, so Agnes Muncy is my 5th great-grandmother.

  • The next column, Common Ancestor in Row GEDCOM shows the relationship of my match to the person shown in their GEDCOM file. In this case, the names are spelled exactly the same, but that’s not always the case.
  • The Up/Down Path shows how the two of us are related to each other and descended from our potential common ancestor.

gedmatch up down path

  • The Compare GEDCOM link provides information about all of the common individuals in our trees. I don’t think the GEDCOM IDs are any type of security risk, but I’ve obscured those numbers anyway. At GEDmatch, you can request to compare by GEDCOM ID.

gedmatch gedcom compare.png

  • Finally, the Score column ranks the matches from 1 to 10, with 10 being highest.

The Up/Down Path information illustrates the challenges in making computer comparisons. The information in our trees is similar, but not exact. I’ve spelled Samuel’s name Claxton and my match has spelled it Clarkson. Both are accurate. There was no consistency and descendants spell it differently. Even his military papers were elusive for decades when his widow filed a claim because the name was spelled both ways.

What Else Can I Do?

For those of us using DNAPainter to paint our segment matches, this new tool is a goldmine of ancestral segment information that can be attributed to specific ancestors, especially for matches who tested at Ancestry where segment information is not available.

I wrote about DNAPainter, here.

I know what I’m going to be doing for the rest of the day!




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23 thoughts on “GEDmatch Introduces Automated Tree Matching

  1. I guess GEDmatch had to do something, I see very few new matches there any more. Anyone looking them up on a search engine is bound to find their connection to the use of genetic genealogy to solve cold cases, and as we’ve seen with DNA testing companies, the privacy concerns have driven away business.

    I still have yet to see a website or other resource that fully explains how to use either their free or their paid tools.

    • Hi Jo, I understand the site is very overloaded right now. So try again in a day or so. There might be more.

  2. Hurumph. I updated my 5 year old GEDCOM and got – drum roll please – a total of six matches I will wait a few days as you suggest. Great idea – thanks for the info.

  3. I suspect we overloaded their hardware and software. Next thing I need is for them to have software that lets me export the direct line ancestors of a DNA and paper trail match back to our common ancestor as a gedcom file so I can add it to my data easily if it appears to be correct. I did a print screen and save as jpg and upload to an ocr conversion site so I have a plain text copy of one match. Also copied their connection to our common ancestor from the pedigree chart. Slow! Report said we had a 13 cm match and the “Q” software said 7.7 with a Q number of 51.00 on Chr 22.

    Of 89 possible matches, the closest match was 5 generations out. Number of generations to our common ancestor was reported as one more than my Legacy program says it is.


  4. I don’t see that link. Are they slowly rolling it out? I have uploaded my GEDCOM but the only things marked NEW are Law Enforcement video and Ancestor Projects.

    • Someone who is not a Tier 1 subscriber sent me a screen shot and she does not have the link. I do. Some do and some don’t, it appears. I have notified GedMatch.

  5. I’ve tried three times and it has stalled at 80% twice, and once said it was finished but gedmatch still shows I have nothing loaded. ???

    • The servers got overwhelmed. The are working to remedy the situation. I think it was more popular than they expected. That’s good news for us as soon as they get the problem resolved.

  6. At the bottom of the screen where it says it finished, it shows this:
    Finished building name table with 27758 individuals (358830 lines).
    (438) ERROR in input: 0 TRLR

    • I just reached out to GEDmatch and the limit is 10,000 people. This is focused on direct ancestors, which is by the limit. That affects my file too. So you’ll need to whittle it down a bit of only create a file with direct ancestors – at least for now.

      • Anyone who has been researching and tree-building for years is going to have more than 10K people. I’m doing as you suggested, made a duplicate tree to cut lines on. It’ll take several days to get that done, but I think it will be worth it.

  7. “MRCA” stands for “most recent common ancestor” . GEDmatch’s recent new automated tree matching tool for Tier I members is fascinating, but I don’t see how it identifies the most recent common ancestor for anyone shown as my autosomal DNA match. Autosomal DNA can be traced only to ancestors five, or perhaps six generations back from a tested individual. Thus other comparison charts reflect 5th cousin relationships, but nothing further back. What I’m seeing on the new tool is common ancestors very far back, from 7 generations to 12 generations, depending on lineages stated in GEDcom trees. Isn’t it misleading to characterized these far back common ancestors as the most recent common ancestor of two autosomal test subjects?

      • This turned out to be a menu display issue.

        The tool was never gone. I had a couple of rounds with the GEDmatch support people. But the MRCA tool was missing from the grayed out menu for non-Tier One members for a couple of weeks. Tier One members saw a different menu in which the MRCA tool was showing.

        The MRCA Tool now appears on the grayed-out menu as well as another new Surname tool. I hope you will review this tool soon.

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