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 C64), 3...Bc5, is possibly the oldest defence to the Ruy Lopez, and has been played occasionally by former world champion Boris Spassky and Boris Gulko. White's most common reply is 4.c3, when Black may choose to play 4...f5, the Cordel Gambit, leading to sharp play, after which 5.d4 is considered the strongest reply. More solid for Black is instead, 4...Nf6, when 5.0-0 0-0 6.d4 Bb6 leads to the Benelux Variation. White's principal alternative to 4.c3 is 4.0-0, when Black can transpose to the Classical Berlin with 4...Nf6 or play 4...Nd4 which isn't so bad for Black. An alternative for White