AncestryDNA changed the algorithm that they use to show matches recently (see AncestryDNA’s Cutting-Edge Science Gets Even Sharper posted by Ancestry Team on May 2, 2016, tagged AncestryDNA, on the Ancestry Blog)
The changes were discussed on several blogs, including Judy G. Russell's The Legal Genealogist (AncestryDNA Alert posted on Posted on April 19, 2016), who links to other discussions at the beginning of her post.
As referenced above in some of the articles and the DNAeXplained: Ancestry Changing their Autosomal Chip May 15, 2016 they are also changing the chip they do the tests which is causing these changes.
Come chat about how the changes have affected you, what techniques you use to keep track of your matches, and other concerns with keeping up with your matches.
If you have any ideas for future topics, post them as answers to Weekly genealogy chat topics - now a week long event! and they might be used in an upcoming week!