New Gedmatch Tool: Find common ancestors (MRCA) from DNA matches

One of my favorite DNA websites, Gedmatch, just came out with a new tool.  This is pretty cool.  The tool will compare your attached Gedcom against the Gedcoms of your matches, and report ancestors in common.

Here is my result when running the tool on my kit:




The short minute or so to run this tool saves a lot of time compared to the time to search through all of these trees manually.

The first three columns of the results are identifying info about the match: kit number, name, and email.  Then a link to their tree, and the size of their match.

Next are the ancestor name in your tree, how many generations back from you that person is in your tree, the ancestor name in the match’s tree, and how many generations back from the match that person is.

The Up Down Path shows a cool graphic with the generations up and back from those common ancestors.  For example:


I really like how they formatted this chart.  The generation labels down the center are a nice touch.

Next the Compare Gedcoms link leads you to the Gedmatch tool “2 GEDCOMs Comparison” with the kit numbers filled in.  Gedmatch was originally created as a Gedcom match tool.  Run this to see all potential matches in your trees, not just the first one.

For example:


Gedcom ID brings up the match’s Gedcom.

Score is a rating of the match from 1 weakest to 10 strongest, according to how well the common ancestors match up.  I received a score of 8 or 9 even when using the same Gedcom, so there may not be many 10’s.  A lower score is an indicator that you should be more careful accepting the match.

Some caveats using the tool:

  • You need to be a Tier 1 Gedmatch subscriber.  The cost is $10 for a month, and helps sustain the site.  You won’t be auto-renewed the next month unless you request that, a nice feature.
  • You need to have a Gedcom attached to your kit.  This is just a good idea anyway, and helps everyone with their research.
  • The tool won’t identify either match as an ancestor of the other, even if the tree says they are.  This isn’t a major problem because you probably don’t need this tool to tell you what the relationship is when it is that close, but an inaccuracy nonetheless.
  • Not everyone attaches their Gedcoms to the DNA testers correctly.  Do a sanity check if the Gedcom match looks long deceased.

Overall, the new find MRCA tool can save a lot of time finding out how a kit is related to other matches.  It can also introduce you to other tools on the site, like 2 GEDCOMs Comparison, that you may not be using yet.  To use the tool you do need to be a subscriber and have a Gedcom attached to a kit.  Please consider doing both of these things, because they help the genealogical community.

Happy searching!


Posted in DNA

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s