Where to look - Shared matches

[ptdrifter]

Hi all
I have a 2nd cousin showing in my match list, and i know who he is exactly where he fits in.
I share roughly 50 matches with him that are 4th cousins or 3rd cousins once removed or thereabouts to us both, and also mostly  the same relationship to each other.
I and my 2nd cousin are both originally Londoners, all the matches in question are all in USA and are all African American. I do have a tiny amount of African DNA according to Ancestry
Any ideas as to our MRCA

[jorose]

There are various types of analysis like WATO that you can use to figure this out.  Some are on https://dnapainter.com/tools

Basically, you want to look at what matches you share, but also matches you don't.
For example, does he share matches that are on your father or mother's side of your tree, and so on.

[ptdrifter]

Hi jorose
All matches in question are on my maternal side. My  cousin and I   share my mum's maternal grandparents.
I shall take a look at WATO as you suggest.
Thank you