Re: Ancestry's Drastic Changes Dash Hopes of Finding Connections #dna

Adam Turner

Only the 8.0 cM cutoff is a recent change. The bit about the shared matches was never announced because it is how AncestryDNA has always worked, at least since I tested.

Your main match list (the screen you are brought to when you click "DNA matches", which shows all of your matches) showed, and continues to show, all matches: everyone from "close family", "2nd-3rd cousins," "4th-6th cousins" (3500+ cM down to 20.0 cM) to "Distant Cousins" aka "5th-8th cousins" (20.0 cM down to 8.0 cM). The change that AncestryDNA made in August is that the cutoff used to go down to 6 cM, and they took out all matches between 6.0 and 8.0 cM. 

The shared matches tab is what you're brought to when you click on the profile of one of your matches, and are trying to triangulate the results and see other people who match both you and that match. This section has always had a cutoff of 20.0 cM; you cannot drill past 20.0 cM from this tab within a match's profile. But you could, and still can, see matches from 8-20 cM in your main match list. 

There's an interesting debate to be had on whether revising the cutoff from 6 cM to 8 cM was beneficial for users (apparently, until 2016, it used to go down as low as 5 cM), as well as the degree to which some of these changes are really motivated by the desire to improve accuracy, as opposed to AncestryDNA's engineers demanding this from within because their job of running a gigantic match database while minimizing bugs is hard. (Seen the "our backend servers are overtaxed at the moment" message lately? I know I have.) But they didn't take 8-20 cM matches out of Shared Matches; they were never there in the first place.

Adam Turner

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