@judge-mentals — Thanks for using nRelate on your site. Unfortunately, we don’t support tag and category matching for related posts right now but this is a feature we are working on for the upcoming build of our plugin.
As a note, our algorithm currently works by weighing title and description, plus context, (among a few other things) to determine which posts are related to each other.
Let us know if you have any other questions or need more help. We also have a support forum at nrelate.com/forum