Ruy Lopez long reign as World Champion". The main replies for Black are 4...d6 and 4...Bc5. In both cases, White commonly plays 5. c3. An uncommon and dubious reply is 4...Ne7, which tries to set up the Mortimer Trap. The Berlin is assigned "ECO" codes C65–C67. Code C65 covers alternatives to 4.0-0 as well as 4.0-0 Bc5. Code C66 covers 4.0-0 d6, while C67 is 4.0-0 Nxe4. Less-common third moves for Black: Ruy Lopez The Ruy Lopez (; ), also called the Spanish Opening or Spanish Game, is a chess opening characterised by the moves: The Ruy Lopez is named after 16th-century
Ruy Lopez, Exchange Variation than this. White now threatens 6.Nxe5 because the sequence 6...Qd4 7.Nf3 Qxe4 to regain the pawn, now fails to 8.Re1 pinning and winning the queen. "ECO" code C68 examines these responses to 5.0-0: 5...Qf6, 5...Qe7, 5...Bd6, 5...Qd6, or 5...Bg4 (all directly defending the e5-pawn, except 5...Bg4 which indirectly defends by pinning the knight). The moves 5...Be6, 5...Be7, and 5...Ne7 are less common moves which have never achieved popularity. The idea behind these moves is that if White plays to win a pawn with 6.Nxe5, 6...Qd4 7.Nf3 Qxe4 is again playable, as the Black minor piece on e6 or e7 blocks