If you can read the dust jacket, you know the gimmick here. Seventeen writers contributed stories, but we aren't told which story is by which writer. So you have to read the story and decide who the writer is, based on the style. There's no answer key, but there's a cryptogram at the beginning of each story. You're told how to solve the cryptograms in case you can guess the writer, though by the time you work through all that, you might have lost interest in figuring it out.
The authors who contributed stories are John Ball, Robert Bloch, Dorothy Salisbury Davis, Rosemary Gatenby, Michael Gilbert, Elizabeth Gresham, Joe L. Hensley, Edward D. Hoch, R. A. Lafferty, John D. MacDonald, Florence Mayberry, Patricia Moyes, Rachael Cosgrove Payes, Bill Pronzini, Ruth Rendell, Lawrence Treat, and Janwillem van de Wetering. I have to admit that I wasn't familiar with some of the names, and I also have to admit that I was surprised to see R. A. Lafferty listed as a contributor. He doesn't turn up in many crime anthologies.
While the good Dr. Asimov doesn't have a story in the book, h e does contribute an eight-page introduction on the topic of writing style that's worth your time. Cheap copies of the book abound on the Internet.