Family Tree DNA’s dual matching algorithm leaves most of the current matches in place, with the newly added portion providing matches for people who didn’t match the old total threshold. The two matching thresholds currently in effect are:
- 20cM total with a minimum longest single segment of 7.69cM
- No total cM requirement but a minimum longest single segment of 9cM
There are lots of happy people reporting new matches on social media today!
You can check your new matches by signing on to your account and clicking on Match Date to sort by match date. A second click sorts in the opposite direction.
However, I noticed that not all of my new matches carry the match date of 5-23-2016, which is the latest match date.
Comparing Your Match Files
The best way to find all of your new matches is to download your matches list and compare to a previous match list. At the bottom of your match page, there is a link to download matches.
I downloaded my match list on 5-23-2016 and again this morning, 5-26-2016, so that I could compare old and new.
My old number of total matches is 1392, and my new is 1447, so my gain would be 55. However, that’s not the entire story.
I compared the two files, and I lost a total of 20 matches. Three of those were in the 4th to remote category and the rest were in the 5th to remote category. These must have been casualties of the tweeking of the algorithm.
In reality, I didn’t gain 55, I gained 75 new matches.
That’s about a 5% increase in matches.
The technique I use to compare the files from the two days is to color code one and then combine them into one spreadsheet file. I sorted by full match name, and that made it easy to look for any two white rows or any two green rows, which indicate a loss or a gain. People appearing in both files will show as a whole and green identical row one after the other forming a green, white, green, white pattern on the spreadsheet, so it’s easy to spot an aberration.
Green is the 5-26-2016 file, so two white rows together means that one of those two white rows from the 5-23-2016 file doesn’t have a corresponding green row, so it was lost in the update. You can see that happened with Jerry, colored red, in my spreadsheet below.
Two green rows together means that one of those green rows didn’t have a 5-23-2016 white row, so it was a gain. You can see that with Helen, colored purple, above. I colored by loss rows red in the Full Name column and my gain rows purple.
Then, I sorted the spreadsheet again by cell color in the Full Name column. All the red and all of the purple appear together, so it was easy to see gains and losses.
Of course, in my example, there is only one gain and one loss, but the concept still holds when there are more.
The one unusual aspect that I found is that the match dates for all of my new matches are not 5-23-2016. They are primarily 5-4-2016 with a few 5-23-2016 and one 5-21-2016. It looks like this rematching process was completed in steps on three different dates.
This means that you can’t rely entirely on the match date on your match page at Family Tree DNA by looking for today’s date. Your best bet is to compare a current matches file with a previous matches file. If you don’t have a previous matches file, it looks like anything in the month of May is likely a new match.
When I evaluated my new matches, I was surprised to find that only 7 were the result of the new algorithm change. I’m not sure if the bottom two would have appeared before, as there were 20.xx cM and I’m not sure if the threshold was exactly 20.0 or 20.99. In any case, they are new now, and the top 5 are definitely a result of the new algorithm.
The balance of my new matches seem to be a result of truly new matches that have recently tested (I received 74 last month alone) or a result of the algorithm tweeking, because they clearly qualified as matches previously, under the old algorithm.
These 67 matches longest block ranges from 7.70 to 12.04 and the total shared cMs range from 21 to 54.
Now, of course, it’s time to see who matches whom, who triangulates, who phases against my mother and which of these matches have trees sharing a common ancestor.
I have a lot of new cousins to meet and genealogy work to do, and I hope you do too. Let me know how the Family Finder update affected you!