Chess is a lot about psychological pressure. A cold-calculating machine’s draw could be a human’s nervous loss. Here’s an interesting position from Koneru Humpy-Ju Wenjun at the Ankara Women’s Chess Grand Prix (Report on Chess Blog.) White is a pawn down. Looks for resources, plays 59.h4. The correct continuation for Black: Bxh4 for a draw (for a machine that is). The h-pawn falls for White, but so does the b-pawn for Black. Now, comes the psychological pressure (in time trouble) that White piles up by pushing the a-pawn knowing that the connected Black’s passers on e- and f-file are controlled by the Bishop. Ju Wenjun fumbles in the endgame, loses. Enjoy the game in the Chess King applet.

Watch how the pressure builds up from Move 60. A machine could handle it in time trouble, but not a human.

Koneru, Humpy – Ju, Wenjun

Result: 1-0
Site: Ankara
Date: 2012.09.23
[…] 1.d4 ¤f6 2.c4 g6 3.¤c3 ¥g7 4.g3 O-O 5.¥g2 d6 6.¤f3 ¤c6 7.O-O a6 8.£c2 ¦b8 9.¦d1 ¥d7 10.e4 b5 11.e5 dxe5 12.dxe5 ¤g4 13.c5 ¤gxe5 14.¤xe5 ¤xe5 15.¥f4 £e8 16.¤d5 c6 17.¤b6 ¥f5 18.£e2 ¤c4 19.¥xb8 £xb8 20.¤d7 ¥xd7 21.¦xd7 ¥xb2 22.¦ad1 ¥f6 23.f4 e6 24.£e4 £c8 25.£xc6 £xc6 26.¥xc6 ¦c8 27.¥b7 ¦xc5 28.¥xa6 ¤e3 29.¦1d2 b4 30.¦b7 ¤d5 31.¦b8+ ¢g7 32.¦c8 ¦a5 33.¥c4 ¥c3 34.¦e2 ¤b6 35.¦c7 ¢f6 36.¥b3 h5 37.¢g2 ¤d5 38.¦b7 ¤e7 39.¦e4 ¤f5 40.¦d7 ¦a6 41.¢f3 ¦d6 42.¦xd6 ¤xd6 43.¦e3 ¥d4 44.¦e1 g5 45.h3 ¤f5 46.¦e4 ¥c3 47.fxg5+ ¢xg5 48.¦c4 ¤d4+ 49.¢e3 e5 50.¦c8 f5 51.¦g8+ ¢f6 52.¥d1 ¥e1 53.¥xh5 ¥xg3 54.¦g6+ ¢e7 55.¦b6 ¥e1 56.¢d3 ¤e6 57.¢c4 e4 58.¥d1 e3 59.h4 ¥xh4 60.¦xb4 ¥e1 61.¦b5 f4 62.a4 ¢d6 63.a5 ¥f2 64.a6 ¤c7 65.¦b6+ ¢e5 66.¦c6 ¤a8 67.¥f3 ¢f5 68.¢d3 e2 69.¢xe2 ¥e3 70.¦c8 ¤b6 71.¦f8+ ¢e5 72.a7
Black resigns because the White a-pawn cannot be stopped without losing a piece and Black has no more resources left.