Using RF to get Ancestry shared matches below 20 cM

I have created a blog and posted it on the FB page but I wanted to post here as well. I am very interested in getting feed back.

I’m pretty sure this is a great feature and worth the time. These steps allow you to search below the 20 cM limit that Ancestry imposes. I found several really good trees between 12 and 20 cM. They provided 3 new geographic locations and many new descendant names.

Feel free to send me a direct email or post comments here.


I use RF for that often, but with the proviso that Ancestry reports ICWs for <20 cM with >=20+ cM matches. I don’t think we get the <20cM ICW with <20cM data

Thanks Jenni, you actually touched on a topic that would like others to comment on as well. I just googled Ancestry triangulations and then watched Andy Lee’s video and article about triangulations at Ancestry.

He likes to use his own phrase “matched triangulations” and he mentions a colleague that used the term “pedigree triangulation”. This video is about a year old but I read all 68 comments and no one mentions only using the “one segment” matches. Your comment above uses “ICWs” matches that are In Common With. But simply using only the one segment matches changes the entire landscape for using these matches. It is my opinion (and I don’t have anyone to back me up on this yet) but I consider these to be true triangulations as described in the first part of my blog. You wont know where the segment is (both chr # and location) until you find this match on a chromosome testing site. But one segment matches between 3 people are only going to be from the same exact Chr # and location. If your parents are related then this all goes out the window. But for the majority of testers this is true. Let me know your thoughts!

btw: the first thing that I do at Ancestry is to add a note 23-1 or 48-3 to represent how many matches and these can be seen without having to click on that person every time. You can even start organizing the lower segment matches -2 and -3 into the specific tow or three groups that they match to by following the -1s in their shared matches list.