Chess opening are so complex and theoretical that amateur players will have trouble understanding them. An example is the Perenyi Attack of the Sicilian Defense (see diagram) which yields an immensely complicated and tactical position that even strong players have difficulty handling, and that is beyond the comprehension of most amateurs. Major changes in the rules of chess in the late fifteenth century increased the speed of the game, consequently emphasizing the importance of opening study. Thus, early chess books, such as the 1497 text of Luis Ramirez de Lucena, present opening analysis, as does Pedro Damiano (1512), and Ruy López de
Sicilian language word has come to us directly from Catalan (as opposed to Provençal or Spanish), the following are likely to be such examples: By the time the crowns of Castille and Aragon were united in the late 15th century, the Italianisation of written Sicilian in the parliamentary and court records had commenced. By 1543 this process was virtually complete, with the Tuscan dialect of Italian becoming the "lingua franca" of the Italian peninsula and supplanting written Sicilian. Spanish rule had hastened this process in two important ways: Spanish rule lasted over three centuries (not counting the Aragonese and Bourbon periods on