Ancestry now showing shared matches with 8-19cM shared?

[4b2]

For the past few days, I've noted that almost every single match I looked at had shared matches, including low cM matches. Previously once you got into those lower cM matches, more would have no shared matches than not.

I just went and checked my 19cM matches that were not assigned to a group; and the reason for that would be that they previously had no shared matches. I would have otherwise grouped them.

I've not got ProTools at the moment. Does anyone have that and able to check if Ancestry now shows shared matches in the 8-19cM range?

Never really made sense why Ancestry didn't provide this. If so, they really need to increase the groups from 64 to 256.

[LizzieL]

Another thread on this here

https://www.rootschat.com/forum/index.php?topic=895650.0

May be a glitch. I'm just making use of it while it's available, in case it reverts to "normal" for us non Pro-tools subscribers.

[ggrocott]

Make the most of it while it's there, it comes and goes!

[ikas]

I've now had shared matches below 20cM for several weeks. I can hardly believe it is still there. Last time it happened it disappeared after 1 day. Long may it continue.

[4b2]

Another thread on this here

I've obvious got confused.

What was the previous setup? It would show shared matches down to 20cM for subscribers? I don't remember it showing the 8-19cM matches with ProTools. I seem to remember wondering why we could not see the 8-19cM matches with ProTools. I'm fairly sure I would have realised that the lower cM matches I had that I could not add to a group (owing to having no matches) had matches.

[Janethepain]

I'm looking at this from a different angle.  I too have now been seeing joint matches down to 6cm ( I marked them not to be deleted maybe 6 years ago?).

I have not been able to spend as much time on Ancestry (the app and the hobby too), for about a year, as my Dad died (nearly 99), and I am his executor (of his will), and because finally and fortuitously, at nearly 70 I have become a grand mother for the first time!  So I don't have much spare time.

Any way, I look after 3 accounts, my own, my Dad's and my maternal cousin's.  I keep waking up realising I have not checked my matches for 3 or 4 weeks, I will spend the best part of a week checking through all the new ones for each account, and then leave it for another 3 weeks and repeat!

Or at least I did, but now with all these extra un-viewed matches showing on the vast majority of new matches, I feel like I am drowning in 'quick checks'! 

These extra matches are of 2 (ultimately one) sources, the first are the under 20cm matches you didn't see, for matches you have already checked, in my case those that went live at the same time or after my account went live. Secondly, the under 20 cm matches of matches I didn't check, because,they went live before I did, so never appeared on the new matches list.

There is a third group as well, that is the over 20cM matches from before I went live, but these would have appeared on my original match list, and I have been through them with a fine toothed comb many a time!

What do others think? I know it depends on how many matches you have, and therefore how feasible it is to check every single one, but for me, being nearly 100% Irish/southwest Scottish, due to emigration to Scotland from Ireland from 1800 on, and one or two from before, I have great Scottish records to use, and many many emigres, from Ireland, and onward from Scotland, who went to all corners of this world, but mainly to the USA, where DNA testing is much more commom than here.

So I have lots and lots of matches already to look into, even before this flood of small matches appeared. I kind of think that the release of these matches may actually be permanent.

Anyway, my point seems to be that the vast majority of these under 20cM matches, and most are u 10 cM or under, only have shared matches of the same cM-age, therefore with no indication of which part of my tree they come from, except from Mother/Father sides. Even if the occasional joint match shows it has a 'family group' match to one of my lines, there is no real evidence that it is through that family line that they match me, it could be another line entirely.

It would be lovely to hear how others feel/see this quandary of mine. I would love to be convinced it is worthwhile continuing, though exactly where I would fit it in, I don't know.

Jane

PS If you think this is bad, you should see my emails!

[4b2]

It would be lovely to hear how others feel/see this quandary of mine. I would love to be convinced it is worthwhile continuing, though exactly where I would fit it in, I don't know.

Jane

PS If you think this is bad, you should see my emails!

If you mean if it's worth pursuing the small clusters, generally I'd say - no. If you do find anything, it usually takes a lot of legwork. I've found that clusters when the largest match is not more than ~29cM (not sure of the exact threshold) are difficult to pin down. That's probably going to be a bit more difficult if your ancestry is Irish and to a lesser extent Scottish, owing to poorer records.

I do have one cluster where the largest matchs are around 12-13cM. That cluster does just graze another cluster in two matches. And of the matches, the point the common line goes back to my ancestral area is in the late 1700s; and then beyond that there is a man born c. 1720 who has a few lines within the matches. So it's quite clear that's the line.

The MRCA is born c. 1660. I do have several other clusters with MRCAs in the 1660 window - none earlier. But those are clusters that have multiple intersections wither more recent generations.

But generally speaking, I've not been able to locate how I'm related to these more distant clusters. It's obviously a bit of pot luck. Of these clusters I've tended to find the MRCAs are further back than you might think. If the largest cM match in a cluster is 20-29cM, I'd expect the MRCAs to be more in the window 1700-1725. While that level also tends to be the ballpark for larger 5th cousins, it just happens that these smaller chunks can end up not getting broken up over a couple of generations. I forget the exact amount, but the average size of a segment from recombination is about 30cM. So while it would be very uncommon to have a 5th cousin with a full 70cM segment in common, a segment of about 25cM can pass unchanged across multiple generations. And there are areas of DNA where recombination is less likely to be recombined.

If you are lucky, you might find an obvious surname in such a cluster. But the odds are against it. These clusters will take you to MRCAs born around 1700. So to match them you'd need to know a total of 256 pairs of 6th GGPs from your tree and your match. And that's not likely, since gaps and dodgy trees proliferate in this period. I've got 64% of my 6th GGPs - let's say 75% wither surnames - so a 25% blind spot where I'm just not going to be able to make the match. Let's say you have a 50% blind spot in your matches' tree. That means there's a 37.5% chance you will be able to locate the MRCAs. Then throw in NPEs, dodgy trees, the issue I mention below, and whatever else - and you're down to a low chance of finding a match.

It would be easiest if your tree is very diverse in localities and your ancestors are all from wealthier parts of England. Most of my ancestors are from the Welsh borders, so it becomes quite difficult to figure out where another Edwards might fit in.

These more distant clusters also tend to have MRCAs shared in the matches which are removed from your actual MRCAs by more than one generation. The chances of matching a 7th cousin on Ancestry is about 1%. So you're looking at people whose more distant ancestors probably happened to have a bigger chunk from one set of MRCAs that remained bigger than average for a few generations. So your matches can cluster on descendants of one nth cousin. The result is you can have a cluster where, say, several matches have MRCAs Robert York (1799) and Catherine Patrickson (1805). But your MRCA might be George York (1727), and you don't have any matches that show that flow. So with such clusters, you often end up with several to a dozen possible MRCAs.

As mentioned above, you can find matches where about 29cM is inherited by a shared match and their child? Over how many generations can 29cM be inherited unbroken? The answer is likely quite large, though increasingly small. And what about 12cM? It's likely some of our shared matches at that level are from the medieval period.

[Janethepain]

Hi,
Thank you for your opinion!  I will make a decision about how to deal with this load of small joint matches, once I see if they are permanent! Hopefully quite soon!!

Jane

[Janethepain]

I have never had much 'mixing' of my sides, in all the ancestry investigations done over the best part of 20 years, and that despite all sides coming from Ireland. However a very obvious 'glitch'* I have noticed is that when checking new matches, I am aware of a pattern, with Maternal matches having joint matches with me which are marked paternal, and vice versa.

*I don't really think that this is a glitch, but rather an aspect of trying to categorise matches, which in all intents and purposes have so very little in common with you/yourself!