How can I use the Largo Related Posts widget to show the right related posts?

If there are specific posts you want to show in the Related Posts widget, you can enter the post IDs in the Related Posts field under Additional Options. You can enter one or more post ids, separated by a comma:

You can find the post ID for a given post by opening it in the Post Edit screen, and finding the ID in the URL:

Note: Manually specified featured posts take top priority. Otherwise largo applies an algorithm to select related posts based on taxonomy and post dates.

If Largo doesn't find any editorially specified related posts (if that field is empty), it then looks at any series the post is assigned to and tries to first find the next (more recent) post in the series. If the post we're looking at is already the most recent post in the series, it will show the previous post in the series.

If the post is not in a series it then looks at categories and tags, sorted by popularity (more frequently used categories/tags get weighted higher) and then again tries to find a more recent post in the most popular category/tag. If it doesn't find any more recent posts it will look for older posts, again also weighing its choice based on popularity.

If that all fails and it doesn't find any posts it will just show the most recent posts on the site.