Editor's Note: Some readers -- already puzzled about why challenger Anatoly Karpov resigned when he did to champion Gary Kasparov in the final game of the world chess championship -- were even more confused Tuesday when Style published the wrong diagram in some editions and an incorrect analysis of how the game would have developed in all editions. Herewith, the correct analysis, along with the correct diagrams.
"You don't win or save chess games by resigning," is an old adage Anatoly Karpov did not follow in his final game against Gary Kasparov. And, indeed, as many chess fans (and computers) found out, Karpov could have had some surprising tricks in a position that looked hopeless for him. Kasparov would have had to play carefully and precisely to score the win.
In the final position (the left diagram), Karpov, playing black, has his king, knight and pawns all immobilized. He can move only his queen, but his options are limited in defending his exposed knight. Kasparov, on the other hand, is free to line up his bishop on the g6 pawn, but has to be careful how he wins the pawn. Once he does it correctly, black's position falls like a house of cards.
Karpov's optimum defense can be summed up in two variations starting from the left diagram. Both ploys are based on queen sacrifices leading to stalemates.
The more subtle one could go like this: 64. ... Qd5 ch; 65. Bf3, Qc5; 66. Be4, Qb4 and now 67. Bxg6 would be a blunder because 67. ... Nxg6; 68. Qxg6, Qb7 ch; 69. Kh2, Qg2 ch; 70. Kxg2 ... or 69. f3, Qxf3 ch; 70. Kxf3, both lead to stalemate.
The other trick is more obvious: 64. ... Qb4; 65. Bf3, Qa3; 66. Be4, Qc5 and here again 67. Bxg6 would be wrong because of 67. ... Nxg6; 68. Qxg6, Qxf2 ch; 69. Kxf2 stalemate. But here the correct move 67. Kh2 leads to a winning position, shown in the right diagram.
In this key position, which also can be achieved via 64. ... Qa3; 65. Bf3, Qb4; 66. Kh2, Qc5; 67. Be4, black's last trick is 67. ... Qb4; 68. Bxg6, Nxg6; 69. Qxg6, Qxh4 ch, hoping for 70. gxh4 stalemate. But white does not take the queen and after 70. Kg2 he will be two healthy pawns up in a theoretically winning position.
It does not even matter whose move it is in this key position: White can force the black queen from the important square c5 by moving his bishop to d3 or b1 before taking the g6 pawn. And there is no doubt that Kasparov could have forced the position on the right diagram anytime.
Karpov could have played on, but we would have missed the fun in finding the win for Kasparov.