Andreas, I run stats about every 2 weeks and, as usual, I'm a little behind (visiting granddaughers...) As of 9/11/17 I have 270 TGs with some Common Ancestor beyond a parent (138 paternal, 132 maternal); and 93 TGs formed with shared segments but no credible Common Ancestor, yet (42 paternal, 51 maternal); and 23 gaps, or filler TGs, with NO shared segments (9 paternal, 14 maternal - usually on the smaller size. A total of 386 TGs that cover all of my DNA. My mother's mother was from 1850s immigrants, which is why I have more no-CA and gap-TGs on my maternal side. I can easily determine the Mbp for each of these - so that's what I use for percentages: 79.7% with CAs, 18.0% w/o CAs, 2.3% gaps Jim Bartlett [email protected] -----Original Message----- From: Andreas West <[email protected]> To: genealogy-dna <[email protected]> Sent: Sun, Oct 1, 2017 1:20 pm Subject: Re: [DNA] Difficulty understand Ancestry's shared matches Hi Jim, I was waiting for you to react to this, as I know we've discussed the point of how many TG's there are. It's obviously determined by the size of these groups (meaning how far one goes back). But when I saw that I immediately thought of your magic 400 number. Now Ancestry uses a minimum of 20cM to show them as shared matches, as I wrote I can only imagine that this is such a large number due to colonial ancestry on her BF's side. Btw, we are still reading the data, she has even more shared matches groups now and it will be interesting to see how many turn out to be TG's. Will surely feedback when we do have a much larger base to calculate on, as you know we're still beta testing with a handful (literally) of users only. Btw, when you say 400 is that with splitting them into the smallest possible groups? Many times we do see TG's where we have smaller TG's at each end which are only connected by some DNA cousins who share the whole segment. That would probably go above 400. Andreas > On 1 Oct 2017, at 20:44, Jim Bartlett <[email protected]> wrote: > > would