Ruy Lopez strengthened when Simen Agdestein and some other Norwegian players adopted the variation. In 1995 Jonathan Tisdall published the article "Ruy Lopez. The Norwegian Variation" in New in Chess Yearbook 37. The Graz Defence, Classical Defence Deferred, and Møller Defence combine 3...a6 with the active move ...Bc5. For a century it was believed that it was safer for Black to place the bishop on e7, but it is much more active on c5. White can gain time after playing d4 as the black bishop will have to move, but this does not always seem to be as important as was once
Open Game and preparing for d2–d4. Black's most common reply is , which usually leads to the Ruy Lopez (3.Bb5), Italian Game (3.Bc4), or Scotch Game (3.d4), though 3.Nc3 Nf6 (the Four Knights Game), often played in the late 19th to early 20th century, or, less commonly, 3...g6 or ...Bb4, (the Three Knights Game), are other possibilities. If Black instead maintains symmetry and counterattacks White's center with then the Petrov's Defense will usually result, though White can avoid the extensive theory of the Petrov by playing 3.Nc3 if he wishes. The Philidor Defence, (2...d6), largely fell out of use after World War