The Elusive DNA Match

The Ancestry DNA Circles Whitepaper is a great resource discussing how Ancestry goes about creating the DNA Circles.

One chart in particular grabbed my attention.

What I find interesting in the above chart is the statistics on tree completeness based on how far back in generations one goes. Notice that only 50% of trees are complete past 5 generations, that's 2nd great grandparents.

Also, I don't know how many of your AncestryDNA matches have trees, but mine sit at around 40%. Of those, maybe 20-30% are useful (more than 100 ancestors in their tree).

So if 30% of my matches have useful trees, and only 50% of those go back 5 generations or more, that means only about 435 (out of 2900) matches are going to the most helpful. (2900 * .3 = 870. 870/2 = 435).

Instead of looking at a DNA match and asking "How are we related?" If you have an established tree, you should be asking, "How does this DNA match corroborate the evidence I have in my tree?".