Ancestry removing matches less than 8cM

[LizzieL]

I can't see any way of deleting them. And if it was just a hint where I am missing a pair of n x great grandparents it wouldn't be so bad. But one potential pair are in addition to the perfectly good pair I have which fit the evidence much better than Ancestry's suggestion.

I have noticed a couple of trees I have looked at in the last couple of days have alternative parents popping up. Far more occurrences than I would have expected if the tree owner just wasn't sure. perhaps this is how it happens. Also I have seen trees where a father and son have the same name (quite common) and the same fragment of ancestors has been added to both, so the son appears to marry his mother. I messaged one such tree owner as the ancestors were shared with me, and he said it just suddenly happened and he couldn't correct it.

[melba_schmelba]

At the top of page when I logged in this morning
"Updates coming soon to DNA matches
We’re making changes that will improve the accuracy and quality of your DNA matches."

At the same time they've tinkered with my thrulines. Added loads of potential ancestors.

I posted the whole text of it and the link to the whitepaper on the previous page 
https://www.rootschat.com/forum/index.php?topic=834432.msg6994574#msg6994574

I know that.
The point I was making was that they claim changes are to improve accuracy and quality of DNA matches.
And at the same time they are introducing things in thrulines that are demonstrably totally inaccurate. Supposed grandfathers fathering children born decades before they themselves were born.
But you chose to cut off the main point of my post.

Oh, it wasn't meant to highlight an omission on your part, just alerting others that they could read it here. I didn't reply to the rest of your quote as I saw you had replied to it yourself and hadn't yet read that.

[stevemiller]

I've just got alerted to this from The DNA Geek, and found it very useful - especially on checking Thrulines,etc (I like visual explanations)

https://thednageek.com/ancestrydnas-2020-matching-white-paper/

[sugarfizzle]

I've just got alerted to this from The DNA Geek, and found it very useful - especially on checking Thrulines,etc (I like visual explanations)

https://thednageek.com/ancestrydnas-2020-matching-white-paper/

Came here to post that link myself.

Worth noting that neither DNA geek nor Peter Calver are suggesting that we go through our whole 6 - 8 cMs matches, there are perhaps way too many to go through for most of us, especially for those that manage multiple DNA accounts.

Both suggest a more targeted approach, both have different suggestions as to how to achieve the target.

Regards Margaret

[LizzieL]

I've just got alerted to this from The DNA Geek, and found it very useful - especially on checking Thrulines,etc (I like visual explanations)

https://thednageek.com/ancestrydnas-2020-matching-white-paper/

In his strategy for triaging his low matches he shows a screen shot of the "Shared DNA" filter - he has entered 6 - 8. I.e he is including 8cM. There still seems to be confusion as to whether we will lose the matches at 8 cM as well as 6 and 7.
As I read the message from Ancestry it will only be 6 and 7

[sugarfizzle]

I've just got alerted to this from The DNA Geek, and found it very useful - especially on checking Thrulines,etc (I like visual explanations)

https://thednageek.com/ancestrydnas-2020-matching-white-paper/

In his strategy for triaging his low matches he shows a screen shot of the "Shared DNA" filter - he has entered 6 - 8. I.e he is including 8cM. There still seems to be confusion as to whether we will lose the matches at 8 cM as well as 6 and 7.
As I read the message from Ancestry it will only be 6 and 7

As I see it, under 8 cMs does not include 8 cMs, but it does include 7.9 cMs.

Look at your close cousin matches, cut off point 20 cMs. My first few 5th to 8th cousins are also recorded as 20 cMs, presumably rounded up from 19.9 cMs.

Similarly with the more distant cousins - the 8s will be preserved, the 7.9s and lower will disappear.

Regards Margaret

[LizzieL]

I hope so, I have enough to check with 6's and 7's without the 8's too.
My strategy so far:
Restrict to 6 and 7 cM with the shared DNA filter.

Then search for all my ancestral surnames. The problem is some have several variant spellings ( A disadvantage when you have some uncommon surnames - whoever mis-spelt Smith or Brown?)
Ticking "include similar surnames" brings up so many completely wrong variants, I have had to search for common variants separately.  This doesn't bring up many as I regularly run this type of search anyway. If there are common ancestors I had the new match to relevant group. I also have a general group for 4th cousins and closer I haven't yet identified the right branch.

Next I search on location. Most of my ancestors are from small villages and didn't move much until late 19th century. I group these with a general location group to look at later. There was so much intermarriage that one of the surnames may be connected even if not my direct ancestor.

The problem with both these searches is that it seems to only pick up linked trees. Most unlinked trees I've looked are small (less than 5 people) and not much use, but some are much larger and contain useful information. perhaps the person just forgot to link them. I have unlinked mine briefly while I did major work on it, but did remember to relink.

Has anyone any further ideas for Operation "Rescue my Rellies"?

[LizzieL]

I sent a message to DNA Geek to query using 6 - 8
and here is the reply
"AncestryDNA rounds the number they show us on the screen. Some matches that show as “8 cM” are safe because they’re 8.0 or higher, but some are, for example, 7.6 cM and scheduled to disappear. Since we can’t see where the list transitions from 8.000 to 7.999, I’m preserving everything that shows as 8 cM. I’ve added a paragraph to the post explaining why I’m using 8."

This very worrying, that the site uses mathematical rules of rounding rather than just cutting off decimal places (7 point anything becomes 7). This would mean about half the matches showing at 8 would really be just under 8 and for the chop.

[Janethepain]

On facebook maths problems - posters always moan about 'old' maths and 'new' maths, and the rules involved (Podemas - the rules of operations etc), and those who know maths of course say maths is maths ( or math, if you are american), and there only ever is one right answer, which ever way, and whenever,  you learned maths!  However, Ancestry seems to have its own wee version here!

Honestly, I remember back a few itterations ago of the DNA screens ,when on a screen that told you about a matches DNA in more detail, it told you more exactly  the match figure (eg 19.5). and the dependability of the match (eg high/low/medium), and what that meant (eg nearly 100% likely to be a true match).  Not all changes have been for the better!  Especially when at one time it is under a border line (eg 20), but sometimes over it. Crazy.

How can a value measured to be under 8.0* be classed at other times as 8 or over 8!

* indcating 'recurring', that is as many 0's as you like!!

Ah well back to checking my 8's now.  I an happy (relatively) with 7's, but decided to deal with 8's before tackling 6's, as there will be even more 6's..... Ahh

Jane