[Event "Stockholm"] [Site "?"] [Round "0"] [White "Petursson"] [Black "de Groot"] [Result "0-1"] [ECO "E70"] [Opening "King's Indian: 4.e4 d6"] 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 O-O 6. Bd3 e5 7. d5 Nbd7 8. Nge2 Nh5 9. Be3 f5 10. exf5 gxf5 11. Qc2 Nc5 12. Bxc5 dxc5 13. O-O-O {White's last move was a preparation for Pg4, which wold lead to a strong attack. Black refutes this scheme in a suprising manner} 13... Qg5+ $1 14. Kb1 Qxg2 $1 { In the present circumstances this is not the kind of greed which we have seen in several of the previous positions in this cahpter. Rather it is a level headed means of removing the sting out of the dangerous enemy pawns.} 15. Rhg1 Qxf3 16. Ng3 Nxg3 17. Rxg3 Qh5 18. Rdg1 Rf7 19. Qg2 Qh6 {Holding everything. Without the help of the sacrificed pawn White has now way of further strengthening his position} 20. Rh3 Qf6 21. Qe2 e4 {Now that Black's united passed pawns begin to roll the day is won. White tries one more desperate offer, which Black accepts with sang-froid as he did the two pawns earlier in the game} 22. Qh5 exd3 23. Qxh7+ Kf8 24. Rhg3 Qh6 $1 25. Qxh6 Bxh6 26. Rg8+ Ke7 27. Re1+ Kf6 28. d6 (28. Ree8 Re7 $1) 28... Rf8 29. Nd5+ Kf7 30. Rgg1 Be6 31. Nxc7 Rae8 32. b3 Bf4 $1 33. Nxe8 Rxe8 34. h4 Bxd6 35. h5 Rh8 36. Rh1 f4 37. h6 Bf5 38. Reg1 d2+ 39. Kb2 Be5+ 40. Ka3 Bc2 0-1