Matches in Common

[larkspur]

Hi, I may be being very thick here.
 But checking through my DNA names. I select  David Smith then the shared matches tab. All I seem to get is "Larkspur does not yet have any matches in common with David Smith." I have thousands of them - not David Smiths obviously  Sorry not explaining this at all well.... Why so many  non connections please?

[Gadget]

They may all share less than 6cM with him.


Add - Ancestry, in it's wisdom, do not show shared matches that are less than 6cM

[larkspur]

Gadget, thank you for getting back so quickly. This I assume, will get worse when Ancestry alters things at the end of August!

[brigidmac]

I get the same thing
With my mothers dna I would expect that when she matces  "jane Jones " by 20cm I would be a shared matches

Occasionally no shared matches shown but i go on  a #jones profile 
click on match to myself
and one does show up after all .

[Petros]

I have a 4th cousin once removed who is a 20 cM match to me but not a shared match with my first cousin on the same paternal line

[LizzieL]

Ancestry doesn't show any matches less than 6 (soon to be 8cM), but doesn't show shared matches more distant than 4th cousin (according to their estimate) .
Some people say this is at the 20cM level cut off, but I think it must take into account the hidden (to us) decimal places.

I have a match with PO at 20 cM (5th cousin - also identified as common ancestor by Ancestry), he and I share two matches. JK at 546cM (1C1R) and DB also at 20cM (Ancestry predicts 4th cousin but he is actually 6th cousin ).
If I look at shared matches with  JK, only shared match with DB shows up not PO, although both are supposed to be 20. Similarly looking at shared matches with DB, only JK shows up because she is well over 20.
It must be that DB is 20.0 or higher but PO lies in the 19.5 to 19.9 range and is rounded up to 20 in what is displayed.

[larkspur]

I just had a message from a 62cM cousin asking me what I thought of our new match, L.P. I do not have her as matching anyone, although she is 21cM!

[durhamgirl73]

Are they a 4-6 cousin or higher?

So when your 62cm cousin clicks on you they can see LP and when they click on LP they see you but when you click on your 62cm cousin you dont see LP and when you click on LP you don't see your 62cm cousin?

[LizzieL]

It seems in this context, Ancestry's idea of 4th cousin or higher is based solely on cM value. I have 3rd cousins (as flagged by Ancestry as Common ancestors /Thrulines and verified by my paper  trail) with unusually low cM (below 20). They do not show up in shared matches even though in reality closer than 4th cousin, because the Ancestry shared match seems completely separate from Thrulines.