Vasily Ivanchuk is back at the board after his disastrous tournament at Sofia and he is taking on Czech number one David Navara in a Rapid match at Prague. After six games Ivanchuk leads 4-2 but here is the one game Navara won.

In this line the game revolves around the status of the knight on a5, will it re-enter the game or just be a lump of dead wood? Navara's thirteenth move 13.b3 spends a whole tempo keeping the knight out of play and creates a huge tactical weakness on the g7-a1 diagonal but as we will see Ivanchuk cannot take advantage and by the time he returns the knight to active operations on c6 Navara's knight is in his guts on d6 and forces the win of a pawn.

D Navara - V Ivanchuk

Cez Trophy Rapid Prague (5)

Gruenfeld Defence g3

1.Nf3 Nf6 2.c4 g6 3.d4 Bg7 4.g3 d5 5.cxd5 Nxd5 6.Bg2 Nb6 7.Nc3 Nc6 8.e3 0-0 9.0-0 Re8 10.Re1 e5

(Black must attack the centre but the knight is forced to the edge of the board)

11.d5 Na5 12.e4 c6 13.b3! cxd5 14.exd5 Bg4

(14...e4 15.Nxe4 Bxa1 16.Bg5 f6 17.Bxf6 Bxf6 18.Nxf6+ Qxf6 19.Rxe8+ Kf7 20.Qe1! and after the rook retreats the knight falls)

15.Ba3 e4

(15...f5!? 16.Bb4)

16.Nxe4 Nxd5 17.Rc1 Nc6

(17...Bf8 18.Bxf8 Kxf8 19.Qd4 Kg8 20.Qxd5!)

18.Nd6 Rxe1+ 19.Qxe1 Rb8 20.Nxb7 Rxb7 21.Rxc6 Rd7 22.h3 Nc3 23.Kh2

(White proceeds to exchange into a won endgame)

23...Bxf3 24.Bxf3 Nb5 25.Qc1 Qe8 26.Rc8 Rd8 27.Bc6 Rxc8 28.Bxe8 Rxc1 29.Bxc1 Nc3 30.a3 Bd4 31.Kg2 Kf8 32.Bc6 Nd1 33.f4 Be3 34.Bxe3 Nxe3+ 35.Kf2 Nc2 36.Be4

(Trapping the black knight and by the time the king comes to support 36.a4 a5 37.Be4 Nd4 38.b4 axb4 39.a5 is also good)

36...Nxa3 37.Bd3 Ke7 38.Ke3 Kd6 39.Kd4 f6 40.g4 Kc6

(40...g5 41.Bxh7 Nb5+ 42.Ke4 gxf4 43.Kxf4 Nd4 44.Bg8)

41.g5

(Fixing black pawns on white squares and making them vulnerable to attack)

41...fxg5 42.fxg5 a5 43.Ke5 Kc5 44.h4 Nb5 45.Kf6

(45.Bxb5 Kxb5 46.Kf6 Kb4 47.Kg7 Kxb3 48.Kxh7 a4 49.h5 a3 50.hxg6 a2 51.g7 a1Q 52.g8Q+ is difficult to win in practice)

45...Nd6 46.Bxg6!

46...hxg6 47.Kxg6 Kd5 48.h5 Ke6 49.h6 Nf7 50.h7 Ke7 51.Kg7 1-0

Just ten days ago Ivanchuk was giving a fine demonstration of how to exploit the offside knight in this line.

V Ivanchuk - L Dominguez

5th MTel Masters Sofia (10)

1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 0-0 5.Bg2 d5 6.cxd5 Nxd5 7.0-0 Nc6 8.Nc3 Nb6 9.e3 Re8 10.Re1 e5 11.d5 Na5 12.e4 c6 13.Bg5 f6 14.Be3 cxd5 15.Bxb6 axb6 16.Nxd5 Be6 17.Qe2 Bxd5 18.exd5 f5 19.b4

(Trapping the knight. Black also wins a piece but reaches an endgame where White's bishop and rook are superior and his passed pawn a menace)

19...e4 20.Rac1 exf3 21.Qxe8+ Qxe8 22.Rxe8+ Rxe8 23.Bxf3 Be5 24.bxa5 bxa5 25.Rc5 b6 26.Rc6 Kf7 27.h4 h5 28.a4 Rd8 29.Rxb6 Rb8 30.Ra6 Rb1+ 31.Kg2 Rb2 32.d6!

(32.Rxa5 Bd4=)

32...Rd2 33.Rxa5 Bxd6 34.Rb5 Kf6 35.a5 Be5 36.Kf1 Bd4 37.Be2 Ra2 38.Rd5 Ba7 39.Rd6+ Ke5 40.Rxg6 Rxa5 41.f4+ Kd5 42.Rf6 Ke4 43.Re6+ Kd4 44.Bxh5 Bc5 45.Kg2 Bb4 46.Bg6 Bd2 47.h5 Ra2 48.Re2 Kd3 49.Kf3 Ra5 50.h6 Bc3 51.h7 Ra8 52.Bxf5+ Kd4 53.g4 Rf8 54.g5 Kd5 55.Kg4 Bh8 56.Re6 1-0

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