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
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