Author Topic: How likely are chance matches of <30 cM?  (Read 454 times)

Offline Petros

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How likely are chance matches of <30 cM?
« on: Friday 19 June 20 08:09 BST (UK) »
Myheritage throws up a lot of lower level European matches for my DNA
e.g. I get 68 matches from France

My ancestry as far back as I can trace, in some lines to the 16th century, is confined to England. So can such matches be rationalised or are they pure chance?

Offline Gadget

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Re: How likely are chance matches of <30 cM?
« Reply #1 on: Friday 19 June 20 09:41 BST (UK) »
If I've understood you correctly, these are people who live in France rather than having French ancestry. 

I have a 2nd cousin that MH describes as Irish. That's because she moved to Eire when she married.

Her Ancestry is Scots/Welsh/English as far back as we have got.


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Offline Ruskie

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Re: How likely are chance matches of <30 cM?
« Reply #2 on: Friday 19 June 20 10:02 BST (UK) »
DNA testing is banned in France. (though Iím sure they find ways around it)  :)

I think My Heritage is more popular in some parts of the world than others - maybe the matches reflect that?


Offline Biggles50

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Re: How likely are chance matches of <30 cM?
« Reply #3 on: Friday 19 June 20 10:34 BST (UK) »
I am in the same boat as you but of those that I have created a valid link to they are located either in the USA, Canada or Australia and have been in those countries for a few generations.

Going sideways and expanding your tree at Great and Great Great Grandparent levels may well lead on to more success in finding and validating distant relatives.

One of my hints is of a second cousin with 364 Cm shared, she has no tree and her Ancestry user name is probably her married name, her forename rings no bells so the chance of finding her is presently zero.  The less the Cm the further distant the relationship and without some common ancestor being found on each tree chances of a successful find must be pretty low.
Col
Lancashire:-Lamb, Gorst, Hardman, Threlfall, Lawson
Westmoreland/Cumberland:-Bush, Strickland, Chamber(s), Hedwen/Hadwin, Carleton
Monmouthshire:-Evans, Jones
Yorkshire:-Collins, Thompson, Darnborough, Drummer, Raistrick, Ewbank, Holdsworth, Clark
Herefordshire:-Ruck, Williams, Jones, Meadmore, Goode, Berrington.
Cheshire:-Ainsworth, Hayes, Norcot, Lowe, Duncalf, Lightfoot, Percival, Newton.
Ireland:-Brazell, Curwen/Curren/Curran/Corn
Canada:-Thompson, Sanderson, Hysop, Beaton, Staniforth

Offline brigidmac

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Re: How likely are chance matches of <30 cM?
« Reply #4 on: Friday 19 June 20 10:46 BST (UK) »
Yes the matches are valid

I set out to find descendants of great grandfather and so traced siblings and their spouses of grandfather
I would not have known their surnames or locations as they mostly emigrated
The most useful was a lady with 18cm to me but 33cm to my mother as she actually had a photo of grandfather's father

Many of the tree s are closed or don't know their ancestors

You can do a surname or location search for matches which will show if they share ancestors even if the tree is closed
Roberts,Fellman.Macdermid MCDERMID McDiarmid Gardner Jones ,Bloch,Irvine,Hallis Stevenson ,McKay

Offline brigidmac

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Re: How likely are chance matches of <30 cM?
« Reply #5 on: Friday 19 June 20 10:49 BST (UK) »
Biggles have you tried mutual matches with that distant cousin

Once you know which side of family they connect to you can message offering for them to look at your tree to confirm connection
Good luck
Roberts,Fellman.Macdermid MCDERMID McDiarmid Gardner Jones ,Bloch,Irvine,Hallis Stevenson ,McKay

Offline melba_schmelba

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Re: How likely are chance matches of <30 cM?
« Reply #6 on: Friday 19 June 20 14:05 BST (UK) »
DNA testing is banned in France. (though Iím sure they find ways around it)  :)

I think My Heritage is more popular in some parts of the world than others - maybe the matches reflect that?
Although in theory that was the case, MyHeritage kits were widely sold in supermarkets in France, possibly still are. However neither Ancestry or 23andme ship to France, and their kits are not sold on Amazon France or anywhere else.

Offline wee Hugh

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Re: How likely are chance matches of <30 cM?
« Reply #7 on: Friday 19 June 20 14:18 BST (UK) »
Forget MyHeritage!

It came up with loads of matches for me, most of them in the USA and few in Britain or Ireland where I would expect the majority of my relatives to be.  A lot of the names appeared to be Jewish, again not something I would expect.

A few were repeats of ones found by Ancestry or 23andme, but in each case MyHeritage claimed a larger number of cM.  Not one of them was someone I recognized as a relative.  I conclude that the people at MyHeritage don't have much idea.
Bagwell of Kilmore & Lisronagh, Co. Tipperary;  Beatty from Enniskillen;  Brown from Preston, Lancs.;  Burke of Ballydugan, Co. Galway;  Casement in the IoM and Co. Antrim;  Davison of Knockboy, Broughshane;  Frobisher;  Guillemard;  Harrison in Co. Antrim and Dublin;  Jones around Burton Pedwardine, Lincs.;  Lindesay of Loughry;  Newcomen of Camlagh, Co. Roscommon;  Shield;  Watson from Kidderminster;  Wilkinson from Leeds

Offline Gadget

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Re: How likely are chance matches of <30 cM?
« Reply #8 on: Friday 19 June 20 14:29 BST (UK) »
in each case MyHeritage claimed a larger number of cM.  N

My Heritage results are higher because Ancestry reduce the number of shared cMs because they assume related by locality rather than descent. None of the other sites do this.  There is a thread on here somewhere - I'll see if I can find it.

My Heritage is better in many respects than Ancestry.
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