Ruy Lopez, Exchange Variation Qf6 7.Qd3. There are two "ECO" classifications for the Exchange Variation. Bibliography Ruy Lopez, Exchange Variation The Exchange Variation of the Ruy Lopez is a chess opening that begins with the moves: Black may recapture on c6 with either pawn; although 4...bxc6 is playable, 4...dxc6 is almost always chosen at master level. Black has gained the at the cost of a weakened pawn structure, due to his doubled pawns on c6 and c7. White aims to reach an endgame in which he has the superior pawn structure, which may become an important factor. Thus, Black is compelled to strive for
Libro de la invencion liberal y arte del juego del axedrez the second part, López introduces the word "gambit" and gives some openings that had not been previously published: the King's Gambit, some variations of the Bishop's Opening, and what is now known as the Steinitz Defense in the Ruy Lopez. The last two parts of the book are critical of the games of Damiano. After the moves 1.e4 e5 2.Nf3, Damiano thought that 2...Nc6 was Black's best move. López considered that inferior because of 3.Bb5. This opening is now known as the Ruy Lopez, although he did not invent it . Libro de la invencion liberal y arte del juego