Patti, I think that it has been too difficult to design an ISOGG chart predicting relationships for the X chromosome because time to common ancestor is so variable. If you look at percentages likely to be in common using Blaine’s chart here, http://www.thegeneticgenealogist.com/2009/01/12/more-x-chromosome-charts/ you will see that there is a big difference between alternating male-female-lines and the all-female lines in average % DNA shared with an ancestor. Every time an X is passed on by a male, there is no observable mixing. Longer X segments can be kept intact for many generations. You really don’t know how far back a common ancestor is. The average autosomal DNA shared in cM is rather misleading in the table at ISOGG because at a low level of matching and low cM, you are much more likely to have an autosomal segment either lost or kept in one generation than to have it sliced up by recombination. I would ignore those low segment size predictions of cousinships in most cases even with the autosomes. Thank you for letting us know that the donor tested at GEDmatch. That is very helpful. If these tests were all at FTDNA, then counting lots of those tiny segments is often ill advised. We also needed to know that TB is a male because a male will not get an X from his father. He gets a Y instead. Males are naturally phased which means the 22 cM largest segment plus the 18 cM segment on the X are significant. Two nice X segments could mean that there are fewer females in the line of descent as you follow the various lines back in time. I would look at TB’s mother’s father’s mother’s side first when comparing with the female “DNA donor”. I think it is normally advisable to use the autosomal predictions and not the X, knowing full well that the cousinship is also highly variable as you go farther away from a first degree relative. In your case, the X may swing the vote to a closer relationship simply because of the distribution and also because one of the X matches in the pair is a male. Not only is the X helpful in directing your search but I also see that many chromosomes (6 autosomes) are involved in the match between TB and your donor. I wouldn’t necessarily call 6 autosomal matches “little” if the same ancestor or ancestral couple is involved. Use the X pattern of inheritance for a male for TB. You will see that there are fewer lines back in time since males only have one X and the X pathways are restricted. If there is a lot of consanguinity though, segments on multiple chromosomes may not all be coming from the same common ancestor. Under normal circumstances having a robust X match plus an autosomal match often means you will be able to find the match within a genealogical time frame. However, if the match partner has unknown paternity that complicates matters. This female probably received this X match from her father coming from the paternal grandmother. The common X ancestor may not be as close as you think. If you can find triangulation with other matches on the X, that may prove helpful in the future. The X narrows the field (unless there is a lot of pedigree collapse) and this kind of autosomal match means that two good pedigrees will likely show a common ancestor. However, this match may not be a real close cousin. The paternity of the cousin is unknown so it will require a lot of effort. It would not surprise me if the matching cousin is anywhere from 2nd cousin once removed to distant cousin when compared to TB (since there could be pedigree collapse) with a very wide range in possibilities. It is still worth pursuing. I can’t tell by your note how TB is related to WD or to MJ. Are WD and MJ supposed to be distantly related to each other and they simply don’t have a DNA match, or do you think they are each related to TB through a different parent of TB? I am also lost by all the initials under MJ and MB. Kathy