Whenever you can make a series of attacking moves and force your opponent to retreat or play defensively, it's tempting to think that you must have some advantage. But that isn't always true. It's important to pay close attention to the “shape” that remains when the forcing sequence is over. If you haven't landed a real blow, you might find yourself suddenly on the defensive.
This is what happened to Gyula Sax of Hungary in his game with Dragoljub Velimirovic of Yugoslavia in the Tungsram international tournament held at Budapest in 1973. In the early middlegame Sax went in for a forcing sequence, failed to achieve anything significant, and then could only sit and watch as Velimirovic's forces came to life. Sax was forced into a pawn-down endgame and he eventually succumbed to Velimirovic's technique.
G.Sax – D.Velimirovic, Budapest 1973 Sicilian Dragon B76
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 d6 6.Bc4 Bd7 7.Bb3 g6 8.Be3 Bg7 9.f3 0-0 10.Qe2 Na5 11.0-0-0 a6 12.Qd3 b5 13.Bg5 Nxb3+ 14.Nxb3 b4 15.Bxf6 Bxf6 16.Nd5 Bg7 17.Qe3 Rb8 18.e5 Be6 19.f4 Rb5 (diagram) 20.Qf3 Bxd5 21.Rxd5 Rxd5 22.Qxd5 dxe5 23.Qxd8 Rxd8 24.fxe5 Bxe5 25.g3 Rd5 26.Re1 a5 27.Nd2 Bxb2+ 28.Kxb2 Rxd2 29.h4 Rg2 30.Re3 f5 31.Rxe7 Rxg3 32.h5 gxh5 33.Re5 Rg5 34.Rxa5 h4 35.Rd5 h3 36.Rd1 Rg3 0-1
The position after 9...0-0 is well known to theory but in place of the standard 10.Qd2, Sax tried the unusual 10.Qe2!? It's hard to know what to make of this move but in any case Velimirovic didn't hesitate to force off his opponent's dangerous bishop with 10...Na5!
Instead of castling queenside, Sax should have recognized that his attacking chances were already behind schedule on account of the slow move 10.Qe2. It was probably better to castle kingside, centralize his pieces, and maintain a solid position.
After 12...b5 Sax did not realize how quickly the tide was turning against him; otherwise he might have tried the centralizing 13.Nd5!?, aiming to neutralize Black's queenside initiative. With the aggressive 13.Bg5?!, Sax started on an adventure that was bound to end badly for him. The idea was to capture on f6, then attack Black's bishop with Nd5, and then play e4-e5. But if Sax had looked closely he would have seen that although this manoeuvre pushes Black around, it doesn't break his position in any way.
If Sax had captured Black's b-pawn with 17.Nxb4, then after 17...a5 he would have been exposed to strong counterplay. But after 17.Qe3 Rb8! Velimirovic was starting to take over, and after 19...Rb5! things became critical for Sax. He could not bail out with 20.exd6 (intending the forking move 21.dxe7 if Black captured on d5) 20...exd6 21.Qf3 because Velimirovic would have the powerful manoeuvre 21...Bxd5 22.Rxd5 Rxd5 23.Qxd5 Qf6! and White cannot defend the square b2.
Sax was now seriously lamenting the exchange of his dark-squared bishop. He tried 20.Qf3 but after the multiple exchanges on d5 Velimirovic played his trump move 22...dxe5. Because his queen was unprotected, Sax was forced to acquiesce to a pawn-down endgame. With the extra advantage of bishop versus knight Velimirovic had no difficulty scoring the full point.