Chess strategy 10 to 25 moves, when players develop their armies and set up the stage for the coming battle; middlegame, the developed phase of the game; and endgame, when most of the pieces are gone and kings start to take an active part in the struggle. 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 Defence. They are catalogued in reference works such as the "Encyclopaedia of Chess Openings". It is recommended for
Ruy Lopez especially if Black plays ...Bb7. White usually plays 9.h3 instead of 9.d4 (the Yates Variation) because after 9.d4 Bg4 (the Bogoljubow Variation), the pin of the white is troublesome. The variation takes its name from the game Capablanca–Bogoljubow, London 1922. The Chigorin Variation was refined by Mikhail Chigorin around the turn of the 20th century and became the primary Black defence to the Ruy Lopez for more than fifty years. With 9...Na5 Black chases the white bishop from the a2–g8 diagonal and frees the c-pawn for queenside expansion. After 10.Bc2 c5 11.d4 the classical Black follow up is 11...Qc7, reinforcing