event suffered a power outage for thirteen minutes while Anand contemplated his 17th move; the organizers later apologized for this mishap, which was caused by an electrical system failure in central Sofia. Game 6, Anand–Topalov, ½–½ Catalan Opening, Open Defense, E03 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.g3 dxc4 5.Bg2 a6 6.Ne5 c5 7.Na3 cxd4 8.Naxc4 Bc5 9.0-0 0-0 10.Bg5 h6 11.Bxf6 Qxf6 12.Nd3 Ba7 13.Qa4 Nc6 14.Rac1 e5 15.Bxc6 b5 16.Qc2 Qxc6 17.Ncxe5 Qe4 18.Qc6 Bb7 19.Qxe4 Bxe4 20.Rc2 Rfe8 21.Rfc1 f6 22.Nd7 Bf5 23.N7c5 Bb6 24.Nb7 Bd7 25.Nf4 Rab8 26.Nd6 Re5 27.Nc8 Ba5 28.Nd3 Re8 29.Na7 Bb6 30.Nc6 Rb7 31.Ncb4 a5 32.Nd5 a4 33.Nxb6 Rxb6 34.Nc5 Bf5 35.Rd2 Rc6 36.b4 axb3 37.axb3 b4 38.Rxd4 Rxe2 39.Rxb4 Bh3! 40.Rbc4 Rd6 41.Re4 Rb2 42.Ree1 Rdd2 43.Ne4 Rd4 44.Nc5 Rdd2 45.Ne4 Rd3 46.Rb1 Rdxb3 47.Nd2 Rb4 48.f3 g5 49.Rxb2 Rxb2 50.Rd1 Kf7 51.Kf2 h5 52.Ke3 Rc2 53.Ra1 Kg6 54.Ra6 Bf5 55.Rd6 Rc3+ 56.Kf2 Rc2 57.Ke3 Rc3+ 58.Kf2 Rc2 ½–½A draw by threefold repetition. 22. Nd7 Anand begins the longest string of knight moves ever seen in a World Championship match. With 39...Bh3! Topalov successfully neutralizes all of Anand's winning chances. Game 7, Anand–Topalov, ½–½ Bogo-Indian Defence, E11 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.g3 Bb4+ 5.Bd2 Be7 6.Bg2 0-0 7.0-0 c6 8.Bf4 dxc4 9.Ne5 b5 10.Nxc6 Nxc6 11.Bxc6 Bd7 12.Bxa8 Qxa8 13.f3 Nd5 14.Bd2 e5 15.e4 Bh3 16.exd5 Bxf1 17.Qxf1 exd4 18.a4 Qxd5 19.axb5 Qxb5 20.Rxa7 Re8 21.Kh1 Bf8 22.Rc7 d3 23.Bc3 Bd6 24.Ra7 h6 25.Nd2 Bb4! 26.Ra1! Bxc3 27.bxc3 Re2 28.Rd1 Qa4 29.Ne4 Qc2 30.Rc1 Rxh2+ 31.Kg1 Rg2+ 32.Qxg2 Qxc1+ 33.Qf1 Qe3+ 34.Qf2 Qc1+ 35.Qf1 Qe3+ 36.Kg2 f5 37.Nf2 Kh7 38.Qb1 Qe6 39.Qb5 g5 40.g4 fxg4 41.fxg4 Kg6 42.Qb7 d2 43.Qb1+ Kg7 44.Kf1 Qe7 45.Kg2 Qe6 46.Qd1 Qe3 47.Qf3 Qe6 48.Qb7+ Kg6 49.Qb1+ Kg7 50.Qd1 Qe3 51.Qc2 Qe2 52.Qa4 Kg8 53.Qd7 Kf8 54.Qd5 Kg7 55.Kg3 Qe3+ 56.Qf3 Qe5+ 57.Kg2 Qe6 58.Qd1 ½–½A draw by threefold repetition. 11...Bd7 is a novelty, as in Gelfand-Ivanchuk, Amber (blindfold) 2010, Ivanchuk had played 11...Ba6. At move 21. Kh1 Anand finally managed to push Topalov out of his prepared line, having spent over an hour on his clock compared to Topalov having spent only 3 minutes. 25...Bb4! 26.Ra1! Topalov played a poisoned move and Anand finds the only response. Other moves such as 26.Ne4 would fail to 26...Bxc3 27.bxc3 f5 28.Nd6 Qc5 29.Rxg7+ Kxg7 30.Nxe8+ Kf7 Game 8, Topalov–Anand, 1–0 Slav Defense: Czech. Wiesbaden Variation,