The Leeds Method sorts your DNA matches into clusters. The members of each cluster are likely descended from a common ancestor or ancestral couple. Finding the common ancestor(s) for a cluster helps us to understand how these matches are related to each other and to us. And this method can help us to verify our ancestors or to break through brick walls.

While the Leeds Method is a powerful tool, unfortunately it cannot help everyone. Can the Leeds Method help you?

Works Well

The Leeds Method works well in the following situations:

If you have “quite a few” 2nd and 3rd cousins

The Leeds Method is based on, and needs, 2nd and 3rd cousins. As a generalization, those are matches between 400 and 90 cM. Although I cannot give an exact number, the Leeds Method often works well if you have at least 6 to 8 matches at this level. And some of them should be in the 200 to 400 cM range.

If you do not have endogamy or pedigree collapse

The Leeds Method works well if you do not have endogamy or pedigree collapse in your tree – or if it is on only one part of your tree. (Note: I will define both terms under the section for when the Leeds Method does not work well.)

If your grandparents are not related & came from different areas

If your grandparents are not related to each other, the Leeds Method works well. It also helps if they came from very different areas so there’s little chance that they might have a surprise connection or that a match might be related to two of your grandparents.

Doesn’t Work Well

The Leeds Method, unfortunately, does not work well in the following situations:

You have endogamy or pedigree collapse in your tree

Endogamy is the practice of a specific group of people marrying within their group for generations. Pedigree collapse is the occasional occurrence of cousins marrying cousins which used to be a fairly common practice. Both of these situations result in your matches being related to each other in multiple ways. And that causes the clusters to merge together instead of creating separate clusters.

However, if you have endogamy or pedigree collapse in just part of your family tree, you can still use the Leeds Method to separate out other parts of your tree.

You have few or no 2nd-3rd cousins

The Leeds Method is based on 2nd and 3rd cousins. If you don’t have any of these matches – or very few – the Leeds Method will not work as intended. However, you can still use it to create clusters with whatever matches you DO have!