Annotated Game #268: When a winning advantage evaporates

In my next "comeback" tournament, I blundered early (move 8) in my first round game after having a distracting morning, which was not worth analyzing beyond remembering the obvious lesson of avoiding that particular blunder again. We'll therefore start with the second round game, which helped highlight the previous theme of Annotated Game #267: How openings are really learned, as it featured a dubious variation from Black in an English Four Knights. I had faced it before twice in my tournament career, but did not recall the previous games at the time. After looking at this one, I should remember the ideas better and be more confident in choosing how to respond (either of two main options for White on move 7 are good for an advantage.)

The new theme for this game is the evaporating winning advantage. In this case, I go up a pawn early and also have a nice positional edge heading into a major and minor piece endgame. This should be an easy win, but I let Black get too much play on the kingside and then end up in a drawn rook endgame, despite retaining the extra pawn. It is a helpful illustration of how quickly even a decisive positional advantage validated by the engines can quickly dissipate, based on some inaccurate calculations and visualization. At least it wasn't a loss, is my only consolation.

[Event "?"] [Site "?"] [Date "????.??.??"] [Round "?"] [White "ChessAdmin"] [Black "Class B"] [Result "1/2-1/2"] [ECO "A28"] [Annotator "ChessAdmin/Dragon 3.2"] [PlyCount "80"] 1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e3 d5 5. cxd5 Nxd5 6. Bb5 f6 {I've faced this twice previously in tournaments. Black is attempting a reversed Sicilian formation, but with a tempo down this weakening of the king position benefits White.} 7. O-O $14 {emphasizing king safety before commencing operations in the center. An immediate d4 is also possible.} Nb6 {seemingly a safe choice, but} 8. d4 $1 $16 Bd7 9. dxe5 a6 $18 {White should now just be winning, after the following.} 10. Bxc6 Bxc6 11. Nd4 {I thought for a while here, and the engine validates my choice. The centralized knight is a strong attacking piece, while Black's king remains in the center and White is also a full pawn up.} Qe7 12. Nxc6 {the clearest road to a positionally won game.} bxc6 13. exf6 {so far so good.} Qxf6 {White now has a decisive positional advantage, with Black's weak doubled c-pawns and king position, but there is no immediate knockout.} 14. e4 {played to control d5 and open up the diagonal for the bishop.} Bd6 15. Qh5+ (15. Be3 $5 {simple development is good.}) 15... g6 16. Qg4 h5 $5 {provocative, but playing it safe won't get Black much either.} 17. Qg5 {I would be happy to trade queens and grind the position in the won endgame.} Be7 18. Qxf6 Bxf6 {With a 4-2 advantage on the kingside and Black's shattered queenside pawns, this should be a simple win.} 19. e5 {a good start, advancing the passed pawn and seizing more space. It is tactically protected.} Be7 (19... Bxe5 $2 20. Re1 $18 {and the bishop is lost.}) 20. Rd1 {perhaps an inaccuracy, although not terrible.} (20. Ne4 {played immediately is good, leaving open where to put the rook. Here if} O-O $6 21. Bg5 $18 {essentially forcing another minor piece trade, bringing me closer to a simplified victory.}) 20... O-O 21. Ne4 {this has less punch now.} (21. g3) 21... Nd5 22. g3 {with the idea of advancing the f-pawn.} Rf5 23. f4 g5 {here I thought for a while and miscalculated the resulting position.} 24. Nxg5 $2 (24. Rf1) (24. Nc3) 24... Bxg5 $16 {Black regains the material.} 25. fxg5 Rxe5 $14 {Black hasn't fully equalized, but his active rooks and centralized knight largely compensate for White's (doubled) 3-1 kingside majority.} 26. Bf4 Nxf4 $6 {this gives back some hope to White, by undoubling the pawns.} (26... Re2) 27. gxf4 $16 Re4 28. Rf1 Rf8 29. Rad1 $2 {unfortunately after the following sequence White has no real threats. It was necessary to get back the material.} (29. Rac1 $1 Rexf4 30. Rxf4 Rxf4 31. Rxc6 Rg4+ 32. Kf2 Rxg5 $2 (32... Rf4+ $16) 33. Rxa6 $1 $18 {and White's outside passed pawn should win.}) 29... Rexf4 30. Rxf4 Rxf4 31. Rd8+ Kg7 32. Rd7+ Kg6 33. Rxc7 Rc4 {now White can't avoid giving Black a passed pawn and we reach a drawn rook ending.} 34. h4 Rxh4 35. Rxc6+ Kxg5 $11 36. Rxa6 Rf4 37. b3 Rg4+ 38. Kf2 Rf4+ 39. Kg2 Rg4+ 40. Kf2 Rf4+ 1/2-1/2