The following complicated position arose in this year's Tromso (NORWAY) tournament between the Serbian grandmaster I.Ivanisevic and the Swedish master J.Sigeman. White has strong attacking chances along the open h-file. For this reason Black made a practical decision and chucked a pawn with 21...c4!? , trying to deflect White from his attack against the Black King and making room for the Knight to enter the fray via the c5-square. If White now takes the pawn with his Knight , then Black exchanges Queens and eliminates the immediate danger. The extra pawn that White would have is partially compensated by Black's 2-Bishops.
Ivanisevic did not take the pawn. Instead, looking deeply into the position, he found a powerful tactical idea that exposes the vulnerable position of the Black Queen. Can you see it? White to play and win!
Sigeman
Ivanisevic
