In order to determine if 3 people have a common ancestor, you need to have the following two requirements:
1. All 3 of them must match each other on the same part of the same chromosome
2. All 3 of them must be in common with each other
I often cannot get my In Common Filter to work on the ftDNA site using the procedure I outlined in my last post. So I switched to using a 3rd party tool designed by Rob Warthen called DNAGEDcom.
In order to use this tool, you must first have all of your match's relationship status assigned. You do so by clicking on the orange "assign" button next to everyone's names.
I assign everyone as “distant cousin.”
In order to determine if everyone is set to a relationship status, I log into my account, change the filter to “Show All Matches” and then I click to download all matches to a CSV file.
I open the downloaded CSV file in excel. Then I sort by “Known Relationship.” And if there are any names with a blank known relationship, I go back into my Family Finder match list and search for them and then I change their relationship to “distant cousin.” I then download again to make sure they all “took.”
Once you have all your matches assigned, then you can go to the website http://www.dnagedcom.com
And register for an account.
Then click the Family Tree DNA button at the top.
Enter your kit id and password and then click the “Get Data” button. It will probably 15-20 minutes to download it all.
A zip file will be downloaded to your computer. Unzip the file and it will contain 3 files – match list, ICW list, and chromosome browser list.
Many Thanks to Rob for developing this wonderful tool~!