After three rounds of the Aegon "Man v Machine" tournament in the Netherlands, the humans hold a slim lead by 761/2 to 731/2. While the best machines are generally performing well, notching up some good wins against grandmasters, there have been moments when the silicon brains have been revealed to have feet of clay. Here is one of the worst examples.

Black's imaginative 18...Nd3??! was a fine idea with a huge hole in it. The combination left Black a piece behind in what should have been a hopeless position. From moves 24 to 28, however, White makes every positional mistake imaginable. First he shunts his rook offside, then he sends his bishop on an absurd pawn-hunt that leaves it totally out of the game. After 27...g5, Black had real chances, and after 28...g4 he was already probably winning.

White: Mephisto Milano Pro

Black: Stefan Loeffler

1 e4 Nf6 24 Rf3 g6

2 e5 Nd5 25 Rh3 Qg7

3 d4 d6 26 Bc8 Re5

4 c4 Nb6 27 Bxb7 g5

5 exd6 exd6 28 Bc6 g4

6 Nc3 Be7 29 Rg3 f5

7 Be2 0-0 30 h3 h5

8 Nf3 Bg4 31 Rf1 f4

9 0-0 c5 32 Rxe3Rxe3

10 b3 Nc6 33 Nd1 Qxb2

11 d4 Bxf3 34 Nxb2 f3

12 Bxf3 Nd4 35 hxg4 fxg2+

13 Re1 Nd7 36 Kxg2 Re2+

14 Bg4 Ne5 37 Kg1 Rxf1+

15 Bh3 Bh4 38 Kxf1 Rxb2

16 Be3 Qf6 39 gxh5 Rxa2

17 Kh1 Qg6 40 Bd2 Rb2

18 Bxd4 Nd3 41 Ke1 Rxb3

19 Be3 Bxf2 42 Kd2 a5

20 Rf1 Bxe3 43 Bf5 a4

21 Bf5 Nb2 44 Bc2 Rb4

22 Qe2 Qh6 White resigned

23 Qxb2 Rae8