With four rounds left to play in the British Championship at Swansea Leisure Centre, Keith Arkell leads with 6 points, followed by Jonathan Parker on 51/2. Among the group on 5 points are two of the three grandmasters competing in the event, Matthew Sadler and Jonathan Levitt. The third grandmaster, Mark Hebden, is having a miserable time, pottering around the middle of the field with only 3 points.

While Sadler had a short but exciting draw in the seventh round with Matthew Turner, Arkell and Parker moved ahead with good wins. Arkell's victory over Aaron Summerscale (who had started the round as joint leader) was a typically patient and risk-free performance and his second win in a row from an endgame with rook, knight and six pawns against rook, bishop and six pawns.

Under normal circumstances, rook and bishop co-operate better than rook and knight, but Arkell has shown excellent judgement and technique in both these games to exploit positional features that have worked in the knight's favour.

The seventh round game was very instructive:

White: Keith Arkell

Black: Aaron Summerscale

Slav Defence

1.d4 d5 2.c4 c6 3.Nf3 dxc4 4.a4 b5?! 5.e3 e6 6.b3 b4

If this is the best Black can do, his whole opening is faulty. White gains total control of c4.

7.Bxc4 Nf6 8.0-0 Nbd7 9.Nbd2 c5 10.Bb2 Bb7 11.Qe2 cxd4 12.Nxd4 Bd6 13.Ba6! Bxa6 14.Qxa6 Qb8 15.h3 0-0 16.Nc4 Bc5 17.Nc6 Qc8 18.Qxc8 Rfxc8 19.N6e5 Nxe5 20.Bxe5 Nd7 21.Rfd1 Nxe5?!

21...Nb6 is better. Now White gets the endgame he wants.

22.Nxe5 Be7 23.Nc4 Rc7 24.Rd3 Kf8 25.Rad1 Ke8 26.e4 Rac8 27.Kf1 Bf8? 28.Ke2 Be7

Black should be playing h5 and g5 to prevent White gaining space on the K-side.

29.f4 Bf8 30.g4 Be7 31.Kf3 Rb8 32.h4!? Bxh4 33.g5 f6 34.Kg4 Bf2 35.Rh3 Rd8 36.Rxd8+ Kxd8 37.Rxh7 Re7 38.Rh8+ Kc7 39.Rf8 Kc6?!

With White's king heading for g6, Black is desperate.

40.gxf6 gxf6 41.Rxf6 Kc5 42.Ne5! Rg7+ 43.Kf3 Bh4 44.Rg6! Rc7

White wins comfortably after 44...Rxg6 45.Nxg6 Bf6 46.Ke3.

45.Rh6 Be7 46.Rxe6 Kd4 47.Nc6+ Kc3 48.Nxe7 Kxb3 49.Nd5 Rb7 50.a5 resigns.