material which justifies the common valuation system Compensation (chess) Evaluation function discusses the difference between a rook and a minor piece References Bibliography External links Relative Value of Chess Pieces Relative Value of Pieces and Principles of Play from The Modern Chess Instructor by Wilhelm Steinitz About the Values of Chess Pieces by Ralph Betza, 1996. The Evaluation of Material Imbalances by Larry Kaufman “The Value of the Chess Pieces” by Edward Winter Mathematical chess problems