23andMe announced back in October that they were updating their matching algorithms to reflect the fact that many of our matches are much more distant than previously suggested and that these more distant matches are a reflection of pedigree collapse which means that we are related to our more distant relatives in multiple ways. 23andMe wrote an interesting blog post here which also includes links to their papers:

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I now have the new matching algorithms. I have signed up to the Premium version of 23andMe so I have 5000 relatives in my match list. My matches now go down to 0.17% (13 cM) and these matches are predicted to be 11th cousins. I've also noticed that all my matches now seem to share more than one segment, presumably because 23andMe ?claim that with their new phasing algorithm they are better able to detect smaller segments down to 5 cM. However, some of the relationship predictions are really weird. As I go down the list I've got matches with ninth cousins and 10th cousins as well as lots of matches with ninth cousins twice removed and 10th cousins twice removed but there are no ninth or tenth cousins once removed which makes no sense at all.

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I only have a handful of identifiable relatives at 23andMe but these closer matches don't seem to have changed too much though I haven't done any comparisons.

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I'm curious to know how other people's matches have been affected by these new algorithms.

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Best wishes

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Debbie Kennett