We know that small segments shared between two individuals can be problematic (see Small Matching Segments – Friend or Foe?), whether the two individuals are closely related or distantly related (or not related at all, as we’ll see). I call small segments (which I usually classify as 5 cM or less) as POISON because it is currently impossible to decipher between which are real segments and which are not.
In the following analysis, I use the wonderful new Match-O-Match tool at DNAGedcom to compare my and my parents’ match lists from AncestryDNA. The Match-O-Match tool is a powerful spreadsheet analysis tool developed by Don Worth. It is available to DNAGedcom subscribers as part of the DNAGedcom Client. For more, see page 10 of the PDF HERE. Thank you Don for this great new tool!