First and foremost this book is about practising to calculate variations. Practise makes perfect. Begin with simple pawn variations, then piece variations, and finally variation calculations with pieces and pawns on the board. The step by step method used ensures a gradual but very effective way towards becoming confident and accurate in your variation calculations. Without mastering this art it is impossible to become an expert in either tactical or strategical calculations. This book will not disappoint the student who wishes to improve his/her variation calculation ability. The training is presented in an interesting non boring way, which is unusual in this category of chess.