The message below was sent to Family Tree DNA Project Administrators today. It looks like they are starting to roll out the requests submitted through the ISOGG Wiki.
Dear Group Administrators,
You asked for it – we listened!
As you may have read in some of the genetic genealogy community blogs, we’ve made some adjustments to Family Finder’s matching thresholds, changes that the genetic genealogy community has requested for several years.
After months of research and testing, we’re implementing those changes as soon as the quality assurance process is complete, which should be within the next few days.
Until now the amount of shared DNA required for two people to show as a match was a minimum of 20 total centiMorgans of shared DNA with a minimum longest block of at least 7.69 cM for 99% of testers, 5.5 cM for the other one percent.
With the adjustment, if two people share a segment of 9 cM or more, they will show as a match regardless of the number of total shared cM. However, if there’s not a block that’s 9 cM or greater, the minimum of 20 shared cM with a longest block of 7.69 cM applies.
We also slightly altered other proprietary portions of the matching algorithm that will, to a small degree, affect block sizes and total shared centiMorgans. These changes should have only marginal effects, if any, on relationships, generally in the distant to remote ranges.
There’s a separate proprietary formula that is also applied to those with Ashkenazi heritage, but you can, of course, expect to have more new matches than those not of Ashkenazi heritage.
The entire existing database has been rerun using the new matching criteria, and all new matches have been calculated with the new thresholds.
Please keep in mind this change will not affect close matches, only distant and speculative ones. Some matches will fall off, others will be added. Most people will likely have a net gain of matches.
Your myOrigins results may change slightly with the rerun, but we have not updated or changed myOrigins yet. We’ll let you know when that happens.
If you have questions that related to your project members’ results, please direct those to email@example.com and one of the Group Projects team will assist you.
And that’s not the only good news we have!
Some of you may have dealt with mtDNA results that had some issues with genetic distance. The fix for the root cause of that problem was released awhile back, but we had to wait until all the hardware installations were complete and integrated before re-running those kits affected prior to that fix. We’re in the process of deploying that update now!
Over the next few days, those affected will likely see differences in genetic distance of some matches as the corrections are implemented. Those who have tested after the fix whose mutations were correct may see an increase in matches to existing testers. That’s to be expected.
Thank you for your patience through the process.
Finally, if you’ll be attending the SCGS Genealogy Jamboree in Burbank next week, Family Tree DNA’s booth will be in the front of the exhibit hall, Booths 401-402. In addition, your Group Projects Manager, Janine Cloud, will be speaking about group projects on DNA Day Thursday at 10:00 am, and your Group Projects Liaison, Jim Brewster, will be speaking Saturday at at 8:30 am (Getting Your Results is Just the Beginning), and Sunday at 12:30 pm (Connecting with Your Eastern European Origins.)
FTDNA will also have a booth at the Ontario Genealogical Society Conference in Toronto, so if you’re attending, be sure to stop by and pick up kits from the team there.
As always, thank you for your support, your patience, and your hard work. We appreciate you!
The Family Tree DNA Team