[Event "London 1979"]  [White "John Nunn"]  [Black "Mark Hebden"]  [Result "1-0"]  [ECO "C29"]  [PlyCount "41"]  [EventDate "1979.??.??"]  [SourceTitle "StarBase 2.88"]  [Source "Pickard & Son"]  [SourceDate "2003.01.15"]  [SourceVersion "1"]  [SourceVersionDate "2003.01.15"]  [SourceQuality "2"]   1. e4 e5 2. Nc3 Nf6 3. f4 {This may be (old) mainline but both} (3. Nf3 {and}) (3. Bc4 {are preferable}) 3... d5 4. fxe5 Nxe4 5. d3 $6 {Ignore what the books say. Stockfish says} (5. Qf3 {is better and that's good enough for me. A sample line is} f5 (5... Nc6 6. Bb5 Nxc3 7. dxc3 a6 8. Bxc6+ bxc6 9. Qf2 $11) 6. d3 Nxc3 7. bxc3 d4 8. Qg3 dxc3 9. Be2 $1 $11) 5... Nxc3 6. bxc3 d4 7. Nf3 Nc6 8. Be2 Bc5 (8... dxc3 {is better, e.g.,} 9. O-O Qd5 $1 $15) 9. O-O dxc3+ 10. Kh1 O-O 11. Qe1 Nd4 12. Bd1 Nxf3 (12... Re8 $1 13. a4 $1 f6 $15) 13. Bxf3 Be6 (13... a5 $1 $15) 14. Qg3 Kh8 (14... f5 $1) 15. Be4 (15. Bxb7 $1 Rb8 16. Be4 $11 {Skaslien-Ruthen, ICCF corr. 1988}) 15... Bd5 $2 (15... f5 $1 16. exf6 Rxf6 17. Bf4 Bd6 $1 18. Bxd6 Qxd6 19. Rxf6 Qxg3 20. hxg3 gxf6 $15) 16. Bg5 Qd7 (16... f6 {puts up more (but futile) resistance, e.g.,} 17. exf6 gxf6 18. Rxf6 $1 Bd6 (18... Rxf6 $2 19. Qh4 $18) 19. Qf2 Bxe4 20. Qd4 $1 Kg8 21. dxe4 Be7 22. Rxf8+ Qxf8 23. Qd5+ $18) 17. Bxh7 $1 Kxh7 (17... Qc6 {prolongs the game without changing the result, e.g.,} 18. Be4 Bxe4 19. dxe4 Qg6 20. Rf4 f6 21. Qh3+ Kg8 22. Bxf6 $1 $18) 18. Bf6 $1 g5 (18... gxf6 19. Rf4 $18) 19. Qxg5 Bxg2+ 20. Qxg2 Rg8 21. Qe4+ 1-0