Hi,
A couple of further points.
Yes heritage matching is a game, based on the companies database.
Hence the recent change in the Ancestry database results.
I have gone from about 60% Scot’s to 60% Germanic, both correct, but from a genealogical point of view the revisal is pointless. It is simply saying that a vast percentage of the population of the UK came from the continent in the last 3 thousand or so years, so we share a lot of DNA.
The Timber algorithm does not have a specific cM cutoff, it is simply that if you have a match who shares multiple short matches, this is likely to be a more distant relative.
The white paper shows that for the Timber algorithm, they have made assumptions that may be true in the USA, though not for longer established families. Which is that people are unlikely to be doubly related.
This is I would say wrong in Europe, before the Industrial Revolution people did move but generally populations were much more stable. So people were much more likely to be doubly related.
The Timber algorithm means that they deliberately throw away match data, (partly at least on financial grounds), which are matches at the 7th to 8th generation level.
This means that you may miss that critical match to the family who know more about their ancestry, and take you back to 1700 or beyond.
In the USA it means that long established families may not be able to match their DNA in Europe, similarly hamstringing research.
See the Ancestry white paper on matching for the detail.
https://www.ancestrycdn.com/support/us/2025/01/2025matchingwhitepaper.pdf
