CHESS
Deep thoughts
Raymond Keene
ome weeks ago in this column (`Henceforward', 17 December) I gave the epoch-making game which the world's top chess computer, Deep Thought, won against Bent Larsen the Danish Grandmas- ter. This week I analyse the game in which The Spectator's Deputy Editor, Dominic Lawson, challenged the metal mind. In- terestingly, in the game which follows, White, perhaps forewarned by the Larsen debacle, adopted a more sensible strategic approach. By doing this, White brought the machine to the very edge of defeat. Things only began to go wrong when both sides' allotted time started to run out. At this point the human player committed a series of tactical errors, caused by the necessity of calculating variations with only a few minutes available. A parallel might be a tough mental arithmetic test with an open-ended series of questions, each to be answered in just a few seconds.
Dominic Lawson — Deep Thought: Queen's Pawn Opening, played by Transatlantic tele- phone link, December 1988 (Half an hour to each player for all the moves).
1 Nf3 d5 2 d4 Nf6 3 Bf4 A sensible opening to adopt against a computer. First it disengages the machine from its 'book'; additionally, it creates a strategic type of position rather than an open tactical one in which computers might excel. 3. . . Nc6? Already DT commits a strategic error. It is suspect to block the 'c' pawn thus in queen's side openings. 3. . . c5 is both obvious and playable. 4 e3 Nh5 5 Bg3 There is also nothing wrong with 5 Bg5 h6 6 Bh4 g5 7 Bg3. 5. . . Nxg3 6 hxg3 e6 7 Bb5 Bd7 8 c3 Perhaps more accurate is 8 Nbd2 developing a piece, keeping the option of c4 and giving the addition- al option of Qe2 in White's arsenal. 8 . . . Bd6 9 Nbd2 f5 To prevent White from playing c4. 10 NM Threatens Oh5+ and so forces Black's hand, for if Black plays the natural 10 • . . Qf6 11 Qh5+ g6 12 Nxg6! Qxg6 13 Qxg6+ hxg6 14 Rxh8+ wins outright. 10 . . . 0-0 11 Ba4 This keeps the bishop defended, but 11 f4 planning Bd3 and g4 to attack on the king's side, looks more natural. 11 . . . Qe8 The computer plays another ungainly move mainly because it can become part of a concrete tactical variation. There is no other discernible merit in 11 . . . Qe8. 12 0-0 Setting a trap based on the predilection for forcing variations evinced by DT. 12 . . . g5 This does not win material and is therefore strategically suspect. However, from DT's point of view it forces events. 13 Nhf3 Nxd4 Not necessary by any means, but it is the logical follow-up to the previous move. 14 Bxd7 Nxf3+ 15 Nxf3 Qxd7 16 NxgS Rf6 The point of this is not clear. Black has no real prospect of launching an attack in the 'h' file. 17 Rcl! Preparing to punch holes in Black's centre. This is the type of quiet strategic play which DT cannot readily handle. 17 . . .Rg6 18 Nf3 b5? An exceedingly dubious advance which actually undermines Black's own centre. DT is trying to stop White from playing c4, but this goal is impracticable. Correct would have been 18. . . c6 to strengthen the black centre. 19 b3! Consistently steering for the key advance c4. 19 . . . c5? Totally inappropriate. Black must keep the defensive resource . . . c6 in reserve. This megalomaniac seizure of territory is com- pletely wrong, not least since it places a target pawn on c5 which impedes the scope of Black's bishop. 20 c4! The logical follow-up to White's 17th and 19th moves.20. . . bxc4 Not 20 . . . dxc4 when 21 Ne5 wins material. 21 bxc4 Qf722 Rbl White's position has become so good that he suffers from an embarrassment of choices over the next few moves. The text is
Position after 30. . . Rd8
excellent, in that it occupies an important open file. Nonetheless, 22 Qd2 or 22 cxd5 exd5 23 Qd3 was also highly tempting. The latter embo- dies the powerful threat of Nh4 or Rfdl, pressing against Black's sensitive pawns on d5 and f5. 22 . . . Rd8 23 Qa4 dxc4 24 Qxc4 Rg4 25 Qa6 Rb4 This reduces some of the pressure. After the trade on b4 Black acquires a queen's side pawn majority. Nevertheless Black's posi- tion remains full of holes and suffers from the disadvantage of numerous scattered pawn is- lands. 26 Rxb4 cxb4 27 Rd 1 Qe7 28 Qc4 h6 29 Rd4! Rd7 30 Qd3 Rd8 (Diagram)31 Ne5! Both this and 31 g4 overload Black's resources and leave DT without sufficient defence. Ominous- ly, though, White was becoming very short of time. Black cannot now, of course, plaY 31. . . Bxe5 on account of 32 Rxd8+. 31 . . . Qc7 32 Nc4? 32 Qb3 Bxe5 33 Qxe6+ Kf8 (best) 34 Qxf5+ Ke7 35 Re4 wins for White. It should be noted, however, that White cannot vary the move order in this decisive sequence. If, erroneously, 33 Rxd8+ Qxd8 34 Qxe6+ Kfg 35 Qxe5 Qdl + 36 Kh2 Qh5+ with a draw, while 35 Qxf5+ fails Lo . . . Qf6. The move in the text dissipates White's edge. 32 . . . Be7 33 WI', This accomplishes nothing but the exposure _01 White's king. 33 g4 is still good. 33 . . . Rxd4 Qxd4 h5 35 Keg? Asking for trouble. 35 . . . Bf6! Just right. This blow demolishes, what remains of White's central domination. It now 36 Qxf6 Qxc4+ 37 Kel Qcl+ 38 Keg Qe2+ 39 Kel Qb1+ and . . Qxa2 with check. The, only chance, therefore, is 39 Kf3 and it
39 . . . Qxa2 40 QdS+ draws, while
ofng clear to Black. 36 Qd3? After thisoffers Whiteh rapidly tied in knots and it is impressive to see how well DT handles positions where (a) it has the advantage, (b) the situation is open and (c) simplification has made pure calculation easier. 36 . Qc6 37 Kfl Qa6 38 Qc2 Bc3! Locking White in. 39 Qb3 Qb5 40 Kgl Qd5 The retreat by White's king into the shelter of its king's side pawns under- scores just how futile was its centralisation at moves 33 and 35. 41 Nay? Premature despera- tion. There were still real drawing chances to be had with 41 Kh2 tucking the king away, e-g- 41 . . . a5 42 Nxa5 QxaS 43 Qxe6+ netting a valuable extra pawn in comparison with the game continuation. Alternatively, 41 Kh2 Kt/ 42 a3 a5 43 axb4 axb4 44 Qa2, when Black's king is hard to shield from checks. 41 . . . Qxa5 42 Qxe6+ Kg7 43 Qe7+ Kg6 44 Qe8+ Kf6 And in, this probably lost position, White overstepped the time limit, thus losing the game.
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