BOOK 11 - THE PROBLEMATIC PIECE
 The subject of the problematic piece, which is treated only in the manuals, is of fundamental importance because of its strategic and tactical repercussions on the game. "One misplaced piece and the whole position is bad," said Tarrasch in one of his definitive and radical statements. Without going to that extreme, in today's chess, where players are used to detecting the slightest favorable or unfavorable nuance, the existence of a problem piece can compromise or limit a player's entire position, and the exploitation of this fact by the opponent can be the path to victory. Chapter 5 of Chess School 2 contains a detailed study of the different cases of a problem piece. In this booklet we will group the exercises into four chapters, with very interesting cases of pieces whose situation on the board is negative.
 There is only one known formula for progress in chess: play as many games as possible, together with theoretical study and analysis of the games themselves. The ideal complement to this formula, as many great masters recommend, is for the player to develop and perfect his tactical and strategic skills by solving numerous exercises, specially selected for their usefulness. Like the ones we offer here.