The pawn has been devalued again on the exchange market. One of the more curious features of changing fashions in opening theory is the way certain gambits come in and out of fashion. A gambit (from the Italian, gambetto: a leg-pull to trip up) is an opening in which one player sacrifices a pawn (or sometimes more) in order to gain time, or open lines of attack, or impress the spectators with his machismo (from the Spanish, machismo: masculinity).

In the 19th century, almost everyone indulged in gambit play. Brilliant attacking play was the mood of the times. As defensive technique developed, however, a simple recipe was found to take the teeth out of most gambits: accept them, then return the material. The gambiteers were subdued and a miserly pawn-hoarding took over.

More recently, however, pawn sacrifices have been back in fashion. In Linares this month, Veselin Topalov notched up two good wins with the Benko Gambit, where Black gives up a pawn for no more than an open file.

The first game is decided by a ghastly blunder. After 23.fxe5 Black mates with 23...Qxh3.

White: Predrag Nikolic

Black: Veselin Topalov

1 d4 g6 13 Rb1 Rfb8

2 c4 Bg7 14 b3 Bxg2

3 Nf3 d6 15 Nxg2 Ng4

4 g3 c5 16 Bb2 Nc7

5 d5 b5 17 Qc2 Bd4

6 cxb5 a6 18 Kh1 Ne5

7 bxa6 Nf6 19 Qe2 Qc8

8 Nc3 0-0 20 f4 Ng4

9 Bg2 Bf5 21 Qf3 Rb4

10 0-0 Nxa6 22 h3?? Ne5

11 Ne1 Qd7 White resigned

12 e4 Bh3

In the next game, White had counted on winning the pawn on d3. Instead it won Black the game.

White: Alexei Dreyev

Black: Veselin Topalov

1 d4 Nf6 16 Nc3 Nxb2

2 c4 g6 17 a4 c4

3 Nc3 Bg7 18 Ra2 Nd3+

4 e4 d6 19 Bxd3 cxd3

5 f3 0-0 20 Bg5 Ba6

6 Bg5 a6 21 Nc7 Nd7!

7 Qd2 c5 22 Ra3 Rfc8!

8 Nge2 Qa5 23 N3b5 Bxb5

9 d5 b5 24 Nxb5 Rc5

10 Nc1 Nbd7 25 Rb3 Rxa4

11 cxb5 axb5 26 0-0 Ra2

12 Nxb5 Nb6 27 Kh1 d2

13 Qxa5 Rxa5 28 Na3 Bd4

14 Bd2 Ra8 29 Rd3 Rc1

15 Ne2 Nc4 White resigned