Chess of the position. Weaknesses in the pawn structure, such as isolated, doubled, or backward pawns and , once created, are often permanent. Care must therefore be taken to avoid these weaknesses unless they are compensated by another valuable asset (for example, by the possibility of developing an attack). A chess opening is the group of initial moves of a game (the "opening moves"). Recognized sequences of opening moves are referred to as "openings" and have been given names such as the Ruy Lopez or Sicilian Defense. They are catalogued in reference works such as the "Encyclopaedia of Chess Openings". There
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