Are you 100% related to your DNA matches on Ancestry?

[sugarfizzle]

Martin, It is a statement regarding ftDNA's matching algorithm, i.e, how they determine a match. They may or may not have changed that since 2016.

At ftDNA my matches appear to show a much bigger match than at Ancestry, because they include small segments in their total figure.

Ancestry has a different algorithm, whereby matches of as low as 6 cMs are considered a match. They reckon that 'Timber' enables them to match at this level with accuracy. Ancestry ignore completely matches less than 6 cMs.

Thus a 25 cMs match at ftDNA, 4 segments, largest 8 cMs, would appear as only 8 cMs at Ancestry.

Which approach is better is perhaps open to question, but the statement as made in the article is not open to question as such, it is a fact.

Regards Margaret

(Modified slightly 16:15)

[Althea7]

Ancestry Thrulines have found me a number of matches at 8cM which are accurate and I wouldn't have picked up on. One set of three, cousins to each other, descended from a Marguerite Howland whose ancestor was halfbrother (different mothers) of my 4xggfather and (slightly higher cMs) a set of 4, cousins to each other but not previously known to each other, descended from my 2xggmother's nephew. cb

Most of my Ancestry Thrulines DNA matches are 8cM, on one segment.  On one of them, I share 8cM on one segment, with two generations, so that tiny bit of DNA got passed down intact.

I don't think Ancestry use anything less than 8cM for Thrulines matches, or if that 8cM is split on more than one segment?

I was looking at one of my Thrulines, where I have two separate matches, where I share 8cM on one segment with one, 4th cousin 1x removed,  and 43cM on three segments with the other, 5th cousin. This relates to two different siblings, born in 1815 and 1833, of my ancestor born in 1828, with the Most Recent Common Ancestors, their father born in 1792, and their mother born in 1797.

So I actually share a lot more DNA with the more distant cousin.

On a different Thruline I can see an 8cM match with a 4th cousin.  I would imagine that is a small amount for a relatively close match?  This relates to my ancestor born in 1817 and their ancestor, his sibling born in 1830, with the MRCA's, their parents, born in 1797.