In his classic work “The modern game of Chess” (1912) Siegbert Tarrasch praised the Open Variation, which gives Black a free game, as being the best continuation against the Ruy Lopez. Many players have followed Tarrasch’s advice and in the late 20th century above all the ever-combative Viktor Kortschnoj was one of its most faithful adherents. In his WCh matches in 1978 in Baguio and in 1981 in Meran he challenged Anatoly Karpov’s Ruy Lopez with 5...Nxe4. 14 years later Viswanathan Anand would employ the Open Variation in his WCh match in New York against Garry Kasparov, though he did so once too oft en as in the tenth game of the match he ran up against the world champion’s fiendish preparation. With 4...Nf6 Black attacks the white e-pawn, with the only difference from the Berlin Defence (3...Nf6) being that the moves 3...a6 4.Ba4 have also been played. But this little detail is extremely important because now Black can shake off the pressure on his Nc6 with b7-b5 whenever he wishes. After 5.0-0 Nxe4 the moves 6.d4 b5 7.Bb3 d5 8.dxe5 Be6 have become established as the main line.