1.e4 c5 2.Nf3 d6 3.Bb5+ Bd7 4.Bxd7+ Qxd7 5.c4 Nc6

In the 1996 U.S. Championship, Kaidanov employed the central lock-up 5 ... e5 against Shaked. Although that cedes to White the permanently better bishop, the idea is that Black, with his unblocked f-pawn, has good chancesfor a kingside expansion. Play continued 6 Nc3 g6 7 O-O Bg7 8 Rb1 Nc6 9 d3 Nge7 10 Bd2 O-O 11 Nd5 Nxd5 12 cxd5 Nd4 13 b4 and White had a significant edge. A radically different approach is the pawn-grabbing 5 ... Qg4, which has been frowned on since Browne-Quinteros, Wijk aan Zee 1974,

where White's lead in development was overwhelming after 6 O-O Qxe4 7 d4 cxd4 8 Re1! Qc6 9 Nxd4 Qxc4 10 Na3. 6.Nc3 g6 6...Nf6 7.d4 cxd4 8.Nxd4 Qg4 is a line for players who are for some reason highly motivated to trade queens; White keeps his small edge in space and development after 9 O-O. 7.d4 cxd4 8.Nxd4 Bg7 9.Nde2 A new approach to the position; there is no need to maintain the knight on d4 with the old 9 Be3 - Shirov's move allows the later development of the bishop to the more active g5. 9...Nf6 10.0-0 0-0 11.f3 a6 12.a4
e6!

Setting in motion a plan to obtain active piece play on the queenside. 13.Bg5 Qc7 14.b3 Nd7 15.Kh1 Qa5 16.Qd2 Nc5 17.Rab1 Qb4!

A good defensive move, which inhibits 18 Bh6 because the reply 18 ... Nxb3 becomes possible. 18.Qc2 18.Qxd6? Rad8 19.Bxd8 Rxd8 20.Qc7 Be5 18...Qa5 An implicit offer of a draw which Shirov rejects. The move was indicated anyway, as otherwise Bg5-d2 might have been very annoying. Note that White still might build up an advantage, as all of Black's potentially freeing pawn breaks have been stymied. 19.Bh4 Nb4 20.Qd1 A very enterprising choice, typical of Shirov. There was nothing wrong with the normal 20 Qd2.

But with the text, Shirov forces the issue, as he is menacing 21 Bh4-e1. 20...Ncd3 Accepting White's kind invitation - and hoping not to be thrown out later! 21.Qd2 Qc5 22.f4 The e5 escape route for the knight has been closed, and 23 Rf1-f3 is in the air. 22...b5! 23.f5!

If 23.cxb5 Rfc8, or 23.axb5 axb5 24.Nxb5 (24.cxb5 Rfc8) 24...Ra2 is very good for Black. 23...exf5 The players are in agreement that Black cannot allow her bishop to be buried as in the line 23 ... bxc4 24 f6. 24.exf5 Rfe8 25.f6 Bf8 26.cxb5 With the long diagonal pressure gone, this move becomes the capture of choice. However, Polgar can now use the open e-file to generate counterplay. 26...axb5 27.Nxb5 Re4 28.Bg3 Rae8 29.Nf4 Better than 29.Nec3?! Re3 30.Bf4 Nxf4

31.Rxf4 Bh6 32.Rc4 Qf5 and Black is threatening 33 ... Qxb1+ among other things. 29...Qg5!!

White would be allowed a more favorable type of simplification after 29 ... Re3 30 Bf2! To avoid this, Polgar is willing to sac the d-pawn as well. 30.Rbd1 Re3 31.Nxd3 Nxd3 32.Bxd6 Bh6 33.Be7 Qh5 This is the position that had to be evaluated to judge the strength of 29 ... Qg5.
34.Qxe3!

Forced but strong; Shirov eliminates the threats against his king (not 34 Qc2? Bf4) and banks on his queenside passers and strong Be7/Pf6 bind to give him winning chances, with rook, knight + 2 pawns against the queen. However, Polgar's queen can roam the open board and may be able to tie down White's pieces to the Defense of his king. 34...Bxe3 35.Rxd3 Bg5 Polgar figures that the bishop would only be a target if it tried to stay on the a7-g1 diagonal. 36.Nc3 Stopping a queen incursion into e2, and heading for a more useful post at d5 where it can help to shepherd in the queenside pawns.

36...h6 37.a5 Qg4 38.h3 Qe6 39.b4 Qa6 40.Rff3 Rc8 41.Bc5 He simply cannot hammer through with 41 Rd6 Qc4 42 a6 Bf4 and Black is becoming alarmingly active. 41...Re8 42.Bf2 This illustrates Shirov's determination. On 42 Be7 Rc8 would amount to a draw offer predicated on the inability of the White bishop to shut the Black rook out of the game. Shirov decides to give the rook free reign, and use the bishop to shield his king instead. 42...Bc1 Looking to dislodge the guardian of the square e2. 43.Rd1 Bb2 44.Nd5 Qc4 45.Bc5 Re2 Allowing White the following small combination in return for engineering a trade of rooks which will give her queen additional operating possibilities. 46.Nf4 Rc2 47.Nxg6 Rc1 48.Rxc1 Qxc1+ 49.Kh2
Qa1

The opening of the g-file is very dangerous, but Polgar is now angling to land a bishop check on e5. 50.Ne7+ Kh7 51.Nc6 Qa4 52.Nd4 A necessary defensive maneuver. 52...Bxd4 53.Bxd4 Qxb4 54.Bb6 Qd6+ 55.g3 Kg6 56.h4 h5 57.Rf4 Qd2+ 58.Rf2 Qb4 59.Kg2 Qe4+ 60.Kh2 Qb4