Oh yea. A good detective novel gives the reader all the necessary information to know the answer. Many lousier novels just keep some essential information hidden until the monologue, because they haven’t got a tricky enough mystery, and really shitty ones just accidentally reveal it, often by over-using tropes or having silly patterns like “it’s always the dark and brooding guy”. Ever read any Dan Brown? In Angels and Demons he gives it away on the first page with an anagram.
That monologue curtain pull is a hallmark of Sherlock Holmes. I wouldn’t call Doyle’s books lousy for that though. Creating brain-teasers for the audience isn’t really the point. It’s all about a character Doyle found insufferable but the audience loved!
