The problem with not showing matches at 12 markers is that you will not be notified if you have a new match with your surname who only tested 12 markers. I was doing something else and looking through one of my participant's 12 marker matches and there was a match with the same surname that could only be seen after clicking to expand up to 1000 matches.(I suspect many casual participants don't even know you can click to see more.) He did not have his preference set to show 12 matches. Consequently he knew nothing of this one and I just happened to stumble on it. Now he can e-mail that match and ask that he upgrade his markers. Martha I agree that this occurs and I can see why. At least for R1b1b2 people, 12 marker matches are almost useless. Mike On Mon, Jun 14, 2010 at 3:45 AM, Debbie Kennett <debbiekennett@aol.com>wrote: > > Often the reason why the matches don't show up at 12, 25 or 37 markers is > simply that people have chosen not to receive match notifications at these > levels. Most people with lots of matches at 12 markers seem to switch off > the 12-marker matches. With R1b and I1 people can sometimes have over 1000 > matches at the 12-marker level. > > Debbie Kennett