1.d4 d5 2.c4 c6 Slav Defence.
3.Nc3 Not the usual move order. Allows 3 ... dxc4 4. e4 the Alekhine Variation. Also allows 3... e5 the Winawer Counter-Gambit, which is never seen in tournament play.
3...Nf6 4.e3 Normal is 4. Nf3.
4...a6 The Chameleon Variation, sometimes called The Main Line. A waiting move that can support ... b5, prevents a piece landing on b5, minimises the effect of Qb3, and keeps the c8-h3 diagonal open for the Bishop. After Qb3 the b7 pawn is sometimes protected by ... Ra7.
5.Bd3 dxc4 6.Bxc4 e6 Closing the diagonal, indicating that the Bishop is going to b7.
7.Nf3 c5 8.0-0 b5 9.Be2 Bb7 10.dxc5 Nc6 11.Nd2 Bxc5 12.Nde4 Nxe4 13.Nxe4 Be7 These Semi-Slav positions often resemble a Sicilian. Put pawns on c2 and d6, move the e3 pawn to e4, the Knight to d4.
14.b3 Nb4 15.Bf3 0-0 16.Ba3 This is cunning, setting up a complicated combination. Black really needs to guard the Bishop on b7 with 16 ... Bd5 or 16 ... Rb8 or 16 ... Qb6.
16...Rc8 17.Nf6+ !
17...Bxf6 Playing with fire. Better to keep guarding the Knight with 17 ... gxf6 18. Bxb7 Qxd1 19. Rfxd1 Rc7! 20. Bxb4 Rxb7! 21. Bxe7 Rxe7 =.
18.Bxb7 ! White keeps the Queens on, thus maintaining the pin on the Knight. Bad would be 18. Qxd8? Rfxd8 19. Bxb7 Rb8 20. Bxb4 Bxa1 21. Ba5 Rf8 22. Bb4 Rfe8 23. Bxa6 Bb2 =+
18...Bxa1 Maybe better is 18 ... Rb8 19. Bxb4 Bxa1 20. Bxf8 Qxd1 21. Rxd1 Rxb7 =.
19.Bxb4 Bf6 ? Black gets lost in the complications. Better is 19 ... Qxd1 20. Rxd1 Rb8! 21. Bxf8 Rxb7!=
20...Qxd1 21.Rxd1 Rxf8 22.Bxa6 22. b4 was actually better, to stop Black's b pawn moving forward. The a6 pawn can be taken later.
22...b4 23.Rc1 g6 24.Rc2 Ra8 25.Bd3 Rd8 26.Be2 Kf8 27.Kf1 Ra8 28.Bc4 Rc8 29.Ke2 Ke7 30.f4 h6 31.Kf3 Rc7 32.g4 g5 33.Ke4 Rc8 1/2-1/2