Are there any available stats—current and historical—for errors behind a pitcher?

In other words, anything that measures whether one pitcher is more likely to have errors committed behind him than another pitcher?

Or is unearned runs the best indicator available?

I’m not aware of any breakdown like that. If you’ve got the skills, you might be able to extract that information using Retrosheet play-by-play files, but that would only take you back to the 1950s.

There’s a real sense of a Retrosheet Era and everything else when it comes to this kind of research.