Matches in pile up zones

[firemonkey]

How good is Ancestry at differentiating between good matches that are within a pile up zone, and false matches that occur within a pile up zone?

[Riverman]

How good is Ancestry at differentiating between good matches that are within a pile up zone, and false matches that occur within a pile up zone?

Ancestry has very few actual false matches in my opinion. Their main problem is that they sort too many good matches out, or reduce them drastically, with their Timber algorithm.
The problem is therefore different from that of MyHeritage, which has some false negative matches too, but even more false positive ones. AncestryDNA on the other hand has way more false negative matches, which means matches they should show, which are real, but being missed.

To the point of children or relatives getting the real match, but the closer ancestor does not, because of the Timber algorithm, even though the older family member shares more DNA.

[firemonkey]

I should explain why I asked. I have quite a few YDNA matches with the surname 'Dutton' who trace their earliest known ancestor back to a Zachariah Dutton born c1750 Maryland. Rather unusually,IMO, I have a 9 cM autosomal match at Ancestry with someone who has Zachariah Dutton as an ancestor. Unfortunately there is no way of knowing which chromosome the 9 cM is on.

I have come across a match at FTDNA, that I had somehow overlooked, with a Eula Dutton Coleman.It's an 11 cM- 1 segment that falls within a pile up area on chr 9. A Joseph Richardson has done quite a lot of research re Zachariah , and is the person to contact re Eula.

I'm now wondering whether the match at Ancestry is also a match on the same pile up region as Eula Dutton Coleman. With the likelihood being that both are false matches.

[Riverman]

I should explain why I asked. I have quite a few YDNA matches with the surname 'Dutton' who trace their earliest known ancestor back to a Zachariah Dutton born c1750 Maryland. Rather unusually,IMO, I have a 9 cM autosomal match at Ancestry with someone who has Zachariah Dutton as an ancestor.  Unfortunately there is no way of knowing which chromosome the 9 cM is on.

I have come across  a match at FTDNA, that I had somehow overlooked, with a Eula Dutton Coleman.It's an 11 cM- 1 segment that falls within a pile up area on chr 9. A Joseph Richardson  has done quite a lot of research re Zachariah , and is the person to contact re Eula.

I'm now wondering whether the match at Ancestry is also a match on the same pile up region as Eula Dutton Coleman. With the likelihood being that both are false matches.

I have similar cases with matches from lineages which are yDNA matches also. The problem is, however, that these are unrelated patterns. The yDNA match is much too distant and the autosomal DNA matches from the same lineage are so old and distant, coming from German migrants to America soon after the founding of the English colony, that there is no way to tell that this segment is really from this ancestor and even if it is, it is unrelated to my yDNA matching.
Such small matches with just one segment, real or not, are hard to pin down. I was able to pin some of them down and they come from big founder events in America. If you have an ancestral person in 30.000 trees on Ancestry, you know that this person could spread a segment to tens of thousands of people, even after 300 or more years.

Therefore its not just about whether that segment is real, it very well might be, but whether its from exactly this ancestor you search for and how it is related to the yDNA matching. These aspects can but don't have to be interconnected.