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 a significant advantage against it in the 18th game. It is solid but slightly passive. Confusingly 9...Nd7 is also called the Chigorin Variation so there are two variations of the Ruy Lopez with that name, but 9...Na5 is the move more commonly associated with Chigorin. This defense is also known as the Keres Variation, after Paul Keres. The Kholmov Variation, 9...Be6, was popular in the 1980s but is now rarely played. The main line runs 10.d4 Bxb3 11.axb3 (11.Qxb3 is another option) exd4 12.cxd4 d5 13.e5 Ne4 14.Nc3 f5 15.exf6 Bxf6 16.Nxe4 dxe4 17.Rxe4 Qd5 18.Rg4, when it has been