When I first took the AncestryDNA test, my friend Anna asked me if I had tested any other members of my family. At the time I remember thinking very clearly that I already had hundreds of matches, the last thing I needed was more matches. Fast forward a few months and my Dad mentioned he would like to do the AncestryDNA test. So as a birthday present I got him an AncestryDNA kit and he took the test. A few weeks later his results came back and he was very happy with the outcome. However for me it turned out to be one of the smartest things I've done since I originally took the test. Now when I get a match that's also a match of my Dad I also know which side of the tree that match is on. It gets much easier to work out the shared relationship. I only have to compare our common match against half my tree.
I asked our ever helpful science team at Ancestry if they could tell me just how much of a benefit I get using both my test and my Dad's. It turns out that with my test alone, the chances of matching a particular 4th cousin in the AncestryDNA database is about 71%. The reason for this is simply that each of us get different bits of DNA from our ancestors and by 4th cousin relationship there is a bigger chance we simply won't match. But having both my test and my Dad's test that number increases to 89%, much better odds. Not only that, the 89% is on Dad's side of the tree. So I get a better chance of finding my 4th cousin but also more precision in working out a common ancestor.
That got me thinking of who else I should try to recruit on my cousin finding mission. Ask my sisters perhaps' Or should I try and get some of my cousins to test, particularly those who are on lines where I have brick walls. The answer to my question is shown in the image below.