[Event "Moscow"] [Site "?"] [Round "0"] [White "Portisch"] [Black "Karpov"] [Result "0-1"] [ECO "A05"] [Opening "Reti: KIA"] 1. Nf3 Nf6 2. g3 b6 3. Bg2 Bb7 4. O-O e6 5. d3 d5 { This is a weak move since it blocks the bishop on b7.} 6. Nbd2 Nbd7 7. Re1 Bc5 {White's last move weakened the f2 square, so Black takes aim at it.} 8. c4 O-O 9. cxd5 exd5 10. Nb3 {The opening is over and Black's pieces are more active. White hopes to start something on the queenside, but his knight is out of play on b3. 10.d4 A more sensible move.} 10... Bb4 11. Bd2 a5 { Black takes some space on the queenside and sets up a possible ...a4.} 12. Nbd4 {12.Bxb4 axb4 Black is better here because White will have trouble defending his pawn on a2.} 12... Re8 13. Rc1 c5 {Now Black has taken control of the d4-square. This means that he can advance the pawn from d5 later, if he so wishes.} 14. Nf5 { The knight looks strong here but it isn't really doing anything.} 14... Nf8 15. d4 Ne4 {Black takes the initiative in the center and renews his attack on f2.} 16. dxc5 {16.a3 Bxd2 17.Nxd2 Qf6} 16... Nxd2 17. Nxd2 Qg5 {A double attack on both White knights. White can't cover both weaknesses by 18.Ne3.} 18. Nd6 { 18.Ne3 Rxe3 19.fxe3 Qxe3+ And Black will take the d2 knight next move with a winning material advantage.} 18... Bxd2 {Now Black forks White's rooks.} 19. Nxb7 {This position is very complicated. White may also play 19.h4 or 19.c6} 19... Bxe1 20. Qxe1 Rxe2 21. Qxe2 Qxc1+ 22. Qf1 Qd2 23. cxb6 Rc8 {White is down a piece and is now faced with 24...Rc1 pinning his queen, so he resigns.} 0-1