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
Ruy Lopez Neo-Steinitz Defence) ("ECO" C71–C76), Black interpolates 3...a6 4.Ba4 before playing 4...d6, which was frequently played by Alekhine, José Raúl Capablanca and Paul Keres. The possibility of breaking the pin with a timely ...b5 gives Black more latitude than in the Old Steinitz Defence; in particular, in the Old Steinitz, White can practically force Black to give up his strongpoint at e5, but in the Modern Steinitz, Black is able to maintain his . Most plausible White moves are playable here, including 5.c3, 5.c4, 5.Bxc6, 5.d4, and 5.0-0. The sharp Siesta Variation arises after 5.c3 f5, while a manoeuvring game results