Test your powers of deduction in this intriguing original new book of chess problems in what is known as retrograde analysis, where the goal is not to determine what will happen, but what must have happened in the games past.Join detective and chess analyst Sherlock Holmes and his intrepid assistant Dr. Watson as they enter The Chameleon Chess Club and employ retrograde chess analysis to examine each of the 70 problems they encounter. Holmes and Watson meet the players, inquire about their rules, examine present board positions, and try to deduce what occurred in the game's past: What was the last move?Is game play up-down or left-right?Was the missing Knight captured on the 18th or 19th move of the game?Can Black castle? (Is it Black's move? Is she in check? Have her King and one Rook remained unmoved?)What color is that piece?Problems get increasingly more complex, sometimes involving chessboards of ambiguous square colors (the chameleon board), ambiguous piece colors and locations, pieces that have been jostled and fallen from the board and more. Games can follow alternate rule forms including homochromatic games (permitting only legal moves between squares of the same color), and heterochromatic games (requiring each move to a square of a different color.)The cast of players is drawn from the world of literature, science and history with their dialogue adding clues about the game play and their own identities, but always reflecting the wit of the author, William Murden.The book is intended for readers with just a basic knowledge of chess pieces and their legal moves. Sherlock Holmes uses Socratic methods, asking leading questions, to school Watson and the reader in the methods and strategies needed for problem solving. Skills learned in earlier, simpler problems problems are reinforced and built upon as the problems get increasingly more difficult.This book of dazzlingly ingenious problems, will capture the imagination of chess buffs, logic puzzle devotees, or even Sherlock Holmes fan looking for new adventures.