Sergash: Tatjana Georgieva Plachkinova is a Woman International Master since 2003. She was born in 1981, and so was 19 or 20 years old when she played the actual game vs Carlsen, who was 10 years old.Plachkinova had then a rating of 2190, vs 2084 for Carlsen. Early 2016, Plachkinova is rated 2096 FIDE.
I went through the game with the program Komodo 9.42 64 bits.
<2...c6> According to my base (Chessbase), this was the first time this was played against Carlsen in a tournament game? Until then there was only 2...e6 (see Carlsen vs J L Hammer, 2001). But Carlsen himself had played 2...c6.
<4...dxc4> Carlsen had preferred 4...e6 here. See H Sorensen vs Carlsen, 2001
<5...Bg4?!> This move appears to be inferior to the most played 5...Bf5 6.e3 e6 7.Bxc4 Bb4 8.0-0 0-0 9.Qe2 Nbd7 10.e4 Bg6 11.Bd3 Bh5 12.e5 Nd5 13.Nxd5 cxd5 14.Qe3 Be7 = Yuri Averbakh vs Semen Abramovich Furman, 21th USSR Championship 1954 in Kiev, 1-0.
<6.e3?!> This is all theoritical, but it seems that none of the players were well prepared for this variation.
Since the knight is not pinned on the queen, better here is 6.Ne5! Bh5 7.f3 Nfd7 8.Nxc4 e5 9.Ne4 Bb4+ 10.Bd2 Qe7 11.Bxb4 Qxb4+ 12.Qd2 Qxd2+ 13.Kxd2 exd4 14.Ned6+ Kd8 (or 14...Ke7 Nxb7
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Valery Chekhov (2510) vs Vladimir Buturin, Army Team Championship, USSR 1983, 1-0) 15.Nxb7+ Kc7 16.Nba5?! (16.Nca5!
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An Lewis (2295) vs J. Menadue (2042), 102nd Great Britain Championship 2015 is Coventry, round 2, 1-0) Na6 = Kick Langeweg (2390) vs Hans Ree (2455), 40th Netherland Championship 1985 in Hilversum, round 11, draw.