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
Spanish influence on Filipino culture Arroyo, the fourteenth President of the Philippines and a hispanophone, reintroduced the study of Spanish into the state school system. There are currently around 3 million Spanish speakers residing in the country, of whom a minority still speak the language in public. The name of the Philippines comes from the king of Spain Philip II. It was given by the Spanish explorer Ruy Lopez de Villalobos who named the islands of Samar and Leyte "Las Islas Felipinas" (The Philippine Islands), during his expedition in 1543. Throughout the colonial period, the name Felipinas (Philippines) was used, and became the official name