In SNP R-M222+ yDNA tests many yDNA surname kits match other surnames than their own because M222 SNP is "young" for at least one reason among other possible reasons.
As you test further marker panels from 12 to 25 to 37 to 67 to 111, the number of matches are usually less with each increasing panel and what is left at 111 is considered related at some degree.
Volunteer admins/co-admins for FTDNA projects can runFTDNA Genetic Distance Reports that produce other FTDNA members that a kit owner has matches with.Admin has use of the FTDNA Tip Report giving estimates of how many generations since the common ancestor for two people.
FTDNA Kit xyz has tested at the 37 marker level.His 37 markers results only give him ONE match in the entire database and that match has a GD of 2.When the Genetic Distance report is run to find matches at the 25 marker level for tested Kit xyz he has 250 matches in the entire database.Not one single match is with his given surname or a variety of same.His one match at 37 is also not with his given surname.
In the 250 hits at 25 tested, he has many repeat matches with DOHERTY, EWING, MCLAUGHLIN, MILLIGAN/MILLIKEN, MCCOMBS, DUNCAN, COWAN, MACADAM, CAREY, DUNBAR, BOYLE and many other prominent M222+ surnames.
However, Kit xyz does not have one single match with MCKEE, MCGEE, MCKIE, MCGHIE, MCGHEE or any variation of same within that entire 250 match list.
Normally, all those first listed surnames also show up as matches with McKee, McGee, McKie, McGhie, McGhee in M222+ in the various members' match list but not with this Kit xyz.
Would there be any known reason beyond coincidence that this would happen?
What, if any info, could be deduced from these results about how it would relate to surnames listed Doherty list of surnames vs McKee list of surnames?