Book excerpt: Have there been times during a game when you have calculated a position for half an hour, only to find out that most of what you were thinking about was of little use? If you have not, maybe the only way to improve your calculation is to upgrade your processor. But if you are human, then this book will offer you practical advice and an effective training plan to think differently and make decisions far more efficiently.In Calculation thinking methods such as Candidates, Combinations, Prophylaxis, Comparison, Elimination, Intermediate Moves, Imagination and Traps are explained to the reader, and ownership of them is offered through a carefully selected series of exercises.