So over 10% of the time, it fails? That's not a great search engine

It's sort of the whole tension when you query vectorized data/embeddings -- you need to balance accuracy and recall against the performance you need.

It took me a while to wrap my head around the two terms since they seem similar -- but Accuracy is basically "did i get mostly good results" and Recall is "did I get most of the good results" and they're subtly different. :)

Those two terms, though, will unlock as deep a rabbit-hole as you'd like on the subject.