With Sherlock Holmes, Arthur Conan Doyle prefigured some forensic techniques that wouldn’t be used for decades. E. O. Heinrich did it in real life. He pioneered a nonexistent field of criminology through innovation, imagination and dogged methodologies.
Over time, book reviewers (and dedicated readers) get better and better at guessing whether or not they will like a book. Descriptions, genres, author history, even cover art all play a factor in deciding if one should devote several hours to a book.