BOOK 9 - DEFENSE AND COUNTERATTACK
 In chess, defense is vital. When attacked, the player is forced to defend tenaciously, trying to take advantage of the opportunities often offered by the attacker's momentum. It's surprising how many games can actually be saved thanks to a strong defense.
 When the offense comes to a standstill, the defender can then take the initiative with the counterattack, the optimal apex of defense that allows the roles to be reversed, usually with predictable results, namely: if the attack was unsuccessful, the counterattack has all the numbers to prevail, since the attacking pieces are usually uncoordinated and leave numerous weak points in their position.
 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