Author Description

This book is all about how a chess engine evaluates chess positions. You do not need to know programming to read this book. This book explains how evaluation works in simple terms. What is evaluation? Evaluation is the process of evaluating a position i.e. assigning a number to a position. It is all about reducing things to numbers. Evaluating positions means that different positions can be compared which helps a player select a move. For example in the initial position the engine could generate a list of all 20 moves for white. For each move it could do these steps: Play the move. Calculate a score for the resulting position. Take the move back. The move with the highest score is the one that is played. In other words it plays what it thinks is best. If it is in a weak position it will play what it thinks gives it the best chances. Chess programs may score many different elements of a position. These include: material. different types of imbalances e.g. 2 minor pieces versus rook + pawn. pawn cover in front of the castled king. weak pawns, including those that are isolated, doubled, doubled and isolated, backward, hanging etc. passed pawns, including those that are defended, supported, connected, separated etc. pawn chains, pawn rams etc. pawn centres. presence of a weak back rank. bad bishops. knights on outposts. bishops and queens on open diagonals. rooks on the 7th rank, rooks on the absolute 7th. rooks on open or half-open files. square control by pieces and pawns. squares attacked near the king. a weak square complex near a king. trapped pieces. pinned pieces attacked pieces. pieces tied in defence. mobility of pieces. You can download a freely available chess engine I have created and set your own values for many of these elements. You can play the engine, or have it play another version of itself and see how it goes. You can change values and see if your can make the engine stronger. It can be quite fun. This may even help improve