Annotated Game #275: An opening shock and a bit of redemption

This final round game put an end to my bad run as Black, thanks to an opening shock that was the proximate cause of my opponent overlooking an unusual knight fork. I've been the victim of such assumptions in the opening phase myself, in which I don't look for tactics (or overlook them) because of the mental presumption that they are not possible so early in the game. Here, the 3...dxc4 line in the Slav after 3. Nc3 is not all that unusual, but most people play 3...Nf6 and I've repeatedly seen surprise on my opponent's faces at the Class level.

Despite being down major material, my opponent still was up for the fight, so I focused my strategy on eliminating any possible counterplay; perhaps some thanks are due to previous study of Petrosian's games. This included giving back some of the material to eliminate White's strongly placed knight, a useful counter-example to some of my past too-materialist thinking, and the decision was fully validated by the engine. Thinking about the board situation in this type of dynamic (rather than static) fashion is what I need to do more. 

[Event "?"] [Site "?"] [Date "????.12.??"] [Round "?"] [White "Class B"] [Black "ChessAdmin"] [Result "0-1"] [ECO "D10"] [Annotator "ChessAdmin/Dragon 3.2"] [PlyCount "66"] [GameId "487233073238"] {[%evp 0,66,19,31,23,-7,26,30,30,-7,-7,-23,-23,-32,-32,-32,-32,-46,-4,-102,-108,-411,-411,-444,-444,-494,-502,-504,-512,-529,-457,-509,-491,-492,-488,-525,-527,-536,-455,-467,-457,-477,-423,-454,-477,-529,-458,-496,-484,-563,-585,-644,-530,-530,-534,-582,-582,-582,-510,-614,-614,-622,-649,-664,-664,-667,-702,-743,-872]} 1. d4 d5 2. c4 c6 3. Nc3 dxc4 4. a4 {my opponent seemed unfamiliar with the move three capture, thought for a bit, then played a standard move preventing (for now) Black's b-pawn advance.} e5 {my opponent had a long think after this, clearly not expecting it.} 5. dxe5 Qxd1+ 6. Nxd1 Bb4+ {I remembered this idea (vaguely) from my opening prep and it certainly seemed best at the board.} 7. Bd2 Bxd2+ 8. Kxd2 Nd7 {a key idea to target the e5 pawn and develop.} (8... Be6 {is also possible and perhaps simpler.}) 9. f4 {this looks obvious to protect the pawn, but now Black's knight becomes strong.} Nc5 $15 {Dragon 3.2 already shows a small but significant positional advantage. I also noted the potential fork on b3 at this time.} 10. Nc3 $4 {my opponent misses the unusual knight fork, no doubt influenced by being in unfamiliar opening territory.} (10. Ke1) 10... Nb3+ $19 11. Kd1 Nxa1 {naturally this is fully winning for Black, but I still have to extract the knight and activate my pieces. So I did not take the win for granted and was careful to examine my opponent's potential counterplay possibilities.} 12. e3 Be6 13. Ne4 {heading for the d6 outpost, no doubt the idea behind the previous move, leaving e4 clear for the knight while opening the diagonal for the Bf1.} O-O-O+ {I thought about this for a while, and Dragon 3.2 agrees that it's best. Black will give back some of the material to simplify and eliminate White's counterplay.} 14. Nd6+ Kc7 (14... Rxd6+ {immediately is also possible and is considered best by the engine.} 15. exd6 Nf6 $19 {the d-pawn is not going anywhere and can be ignored for the short term, while Black gets more pieces into play.}) 15. Kc1 Nb3+ {first extracting the knight, with tempo.} 16. Kc2 Rxd6 17. exd6+ Kxd6 {now I'm a clear piece and pawn ahead and White is not able to develop any meaningful counterplay, although I still have to be careful.} 18. Nf3 f6 {controlling the knight's potential outpost squares at g5 and e5.} 19. Be2 Ne7 20. e4 b5 {reinforcing c4 and mobilizing the queenside pawns.} 21. axb5 cxb5 22. Rd1+ Kc7 {White will not control the open file for long.} 23. f5 Bf7 {keeping an eye on the h5-e8 diagonal.} 24. g4 Nc6 {powerfully activating the knight, which covers some excellent squares in the center and on b4.} 25. h4 Rd8 26. Rxd8 Kxd8 {now I control d4.} 27. Nd2 Ncd4+ {with the forced reduction in available material, there is no longer any real counterplay possibility for White.} 28. Kd1 Nxe2 29. Kxe2 Nxd2 30. Kxd2 Kd7 31. Kc3 Kd6 32. Kd4 {White's king is well centralized and keeps mine from advancing, but now the queenside pawns further mobilize and will eventually win.} a5 33. g5 h5 {designed to neutralize any possibility of a kingside breakthrough. My opponent thought for a while here and then resigned, having no possible prospects for counterplay.} 0-1