These day's there's not many world championship games ultimately decided on the strength of a gambit for black - but in his quest to become the youngest world champion in 1985, Garry Kasparov refined one as he demolished old foe Anatoly Karpov's Sicilian Szen variation (1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nb5 d6 6. c4 Nf6 7. Nb1c3 a6 8. Na3) with 8...d5!? - a move that totally flummoxed Karpov and his team of analysts'. The idea is simple: You sacrifice the d5 pawn for active piece play. It was thus reborn the 'Kasparov gambit' after Kasparov scored 1.5/2 with the black pieces during that world championship tussle - and the game he won, game 16, is hailed by many to be one of the best-ever world championship games. Since then though, refinements have been found that give White an edge. But in his latest Gambit Guide series, GM Boris Alterman believes that despite this, the Kasparov gambit it is still a good surprise weapon for Black to have in his arsenal.