May 5, 1997
Chess | By ROBERT BYRNE
Deep Blue Gently Shows It Has Developed a Nose for Nuances
Once again, Garry Kasparov set out to play a quiet, positional game yesterday against the I.B.M. chess computer Deep Blue, but this time the machine matched him in sophisticated judgment and beat him soundly. On Saturday, Deep Blue had forced Kasparov to give up his strategic approach, only to be defeated at the end when the world champion put on a scintillating display of human tactical brilliance.
Kasparov opened Game 2 with a conservative Ruy Lopez variation (one of the defenses starting with 1 . . . e5). In recent years, he has heavily favored the more aggressive Sicilian Defense. But a year ago, in the fifth game of his first match against Deep Blue, he used 1 . . . e5, presumably to avoid the solid, quiet 2 c3 method with which Deep Blue was confronting his Sicilian. At that time, Kasparov played 2 . . . Nf6 and after 3 Nc3 Nc6 4 d4, Deep Blue had reached a Scotch Opening. This time the play followed classical lines.
After Vasily Smyslov's move, 9 . . . h6, Black figures to keep alive the possiblity of a semi-open center, but Kasparov changed his mind with 15 . . . Na5 and 14 . . . c5, letting Deep Blue block the center with 16 d5.
With 19 a4 and 22 b4, Deep Blue aimed to use its greater control of terrain on the queenside to develop an initiative.
Kasparov soon chose, with 23 . . . c4, to take more queenside terrain to restrict Deep Blue's maneuvering on that flank. But after doubling rooks on the a file, the computer shifted to 26 f4 and 27 fe to open a second front on the opposite wing.
After 28 Qf1, Deep Blue had the initiative and superior mobility. Its immediate threat was 29 ab ab 30 Ra8 Ra8 31 Ra8 Qa8 32 Bh6!, breaking up the black king position.
Deep Blue's 33 Nf5! put powerful pressure on the black defenses. After 33 . . . Bf5 34 ef, it threatened f6! to slice into the king position. Kasparov had to stop this by 34 . . . f6, but placing another pawn on a dark square muzzled his bishop and opened weaknesses on all the light squares around his king.
Deep Blue found a beautiful method of exploiting its superiority with 35 Bd6! Bd6 36 ab ab, opening the a file as the line of march into the black formation. It granted the champion bishops of opposite color -- a common drawing device -- in the recognition that it could not be prevented from infiltrating the black position. It disdained violence in favor of 37 Be4! to blockade the black e pawn so that Kasparov could not hope for counterattack with . . . e5 followed by . . . Qe5.
Kasparov tried to hang on, but he could not parry the queen and rook invasion culminating in 45 Ra6! The decisive positional point was that 45 . . . Qc6 46 dc would make a tiger out of the passed c6 pawn and Deep Blue would complete its infiltrating process by Bd5, Be6 and Kd5, eventually winning both the b and c pawns. A desperate attempt at a perpetual check with 45 . . . Qe3 would fail after 46 Qd6 Qc1 47 Ke2 Qb2 48 Kf3 Qc3 49 Kg4. Kasparov gave up.
In Saturday's game, Kasparov chose the conservative, hypermodern mobilization featuring the fianchetto of both bishops with 4 Bb2 and 5 Bg2. Deep Blue would not allow him to play quietly, however, and counterattacked with great force, eventually touching off a donnybrook with 28 . . . f5.
Grasping the possibilities of the position, Kasparov survived by sacrificing a rook for a bishop with 30 f4!? Be2 31 fg, and pushed ahead behind his g and f pawns in an formidable attack against the computer's king. After 45 g7, Deep Blue could not prevent Kasparov from creating a new queen and called it quits.
Copyright 1997 The New York Times Company