RE: "I've found a higher frequency of matches to third or fourth cousins who have multiple common ancestors, i.e, we have many common (independent) ancestors. AND I've found a higher frequency of matches to cousins who have the common ancestors several times over." I have found the same thing, Patricia. In fact, I am very pleased when I get the occasional unambiguous hit: Only one way that we are likely to be related. All that pedigree collapse seems to increase the numbers of matches we get, but it makes it harder to guess where the shared DNA might originate. The exception is the last case you mentioned, in which cousins have the same common ancestors several times over. That should increase the likelihood that those shared ancestors are the source of the match, right?