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 especially if Black plays ...Bb7. White usually plays 9.h3 instead of 9.d4 (the Yates Variation) because after 9.d4 Bg4 (the Bogoljubow Variation), the pin of the white is troublesome. The variation takes its name from the game Capablanca–Bogoljubow, London 1922. The Chigorin Variation was refined by Mikhail Chigorin around the turn of the 20th century and became the primary Black defence to the Ruy Lopez for more than fifty years. With 9...Na5 Black chases the white bishop from the a2–g8 diagonal and frees the c-pawn for queenside expansion. After 10.Bc2 c5 11.d4 the classical Black follow up is 11...Qc7, reinforcing