Commentary: 2015 U.S. Championship, Round 7 (Paikidze-Melekhina)

IM Nazi Paikidze

The following game is from round 7 of the 2015 U.S. Championship (women's section).  IM Nazi Paikidze as White plays what starts out (via an unusual move-order) as a rather quiet Symmetrical English, but then develops into a war of positional ideas that becomes quite tactical.  Black (FM Alisa Melekhina) missed her best shot to consolidate her position on the queenside with the idea of ...a4 in the early middlegame, leaving her pawn structure shattered afterwards.  White, although a pawn down, never worried about her material deficit, due to Black's long-term inability to cover her weaknesses, and chose a more aggressive plan of play on the kingside.  White's initiative lasts most of the rest of the game, with only a temporary flare-up of activity by Black that only serves to clarify White's advantage.  The ending sequence becomes tactical, through a combination of back-rank threats and the diversion of Black's last defender.  Key themes that occur throughout the game, including the tactics swirling around the e6 pawn, make it worth close study, as well as observing how quiet positional maneuvering can evolve into tactical play.

[Event "ch-USA w 2015"] [Site "Saint Louis USA"] [Date "2015.04.08"] [Round "7"] [White "Paikidze, N."] [Black "Melekhina, A."] [Result "1-0"] [ECO "A37"] [WhiteElo "2333"] [BlackElo "2235"] [Annotator "ChessAdmin/Komodo 8"] [PlyCount "91"] [EventDate "2015.03.31"] [SourceDate "2015.02.07"] 1. Nf3 g6 2. g3 c5 3. Bg2 Bg7 4. c4 Nc6 5. Nc3 {via a somewhat unusual move-order we have arrived at a Symmetrical English. Black will follow the plan of using ...e5 to challenge for control of the center and break symmetry, while White pursues a queenside strategy.} d6 6. O-O e5 {this advance gives Black a lock on d4 and greater central presence/control via her pawns. On the other hand, it blocks the Bg7 and creates a hole on d5.} 7. d3 {this opens up the c1-g5 diagonal for the bishop and also helps restrain a potential future .. .e4 advance.} Nge7 {the standard place for the knight in this variation. The knight, if placed instead on f6, would get in the way of both the Bg7 and the f-pawn, which Black may play to f5 at some point.} 8. a3 O-O 9. Rb1 a5 10. Bd2 {White's dark-square bishop development in this line is somewhat problematic, in that there is no obviously good square for it that does not also get in the way of other pieces. Keeping it on c1 makes no sense, however, so placing it on d2 is fine and the most common option. There it may also help control b4 when the time comes to make a pawn break there.} Rb8 11. Ne1 {initiating the standard plan of repositioning the knight to c2, from where it is able to help White force through the b4 break. This looks awkward at first glance, but in reality the knight is doing little on f3 and moving it also opens up the Bg2 to good effect on the long diagonal.} Be6 {Black similarly has little scope initially for her non-fianchettoed bishop, but there is a more obvious choice of where to place it. From e6, it can help cover the hole on d5 in tandem with the Ne7. Black's subsequent push of the d-pawn is also consistent with the central strategy originally initiated by playing ...e5.} 12. Nc2 d5 13. cxd5 Nxd5 {this recapture is always done with the knight, otherwise White would gain the advantage of the two bishops after exchanging with the Nc3.} 14. Ne4 { an uncommon move. Exchanging on d5 with the knight is more common, as is the alternative Ne3.} b6 {the obvious way to protect the c5 pawn.} 15. Ng5 Bc8 { naturally Black wants to preserve the bishop and avoid giving White the two bishops.} 16. Ne3 {a move that necessarily reflects an understanding of what is happening on the squares g5 and b4. The game is still in the database, which interestingly shows White scoring over 70 percent in the dozen games available, although the position seems quite equal (including to the engine).} Nxe3 (16... Qxg5 17. Nxd5 Qd8 18. b4 $11) 17. Bxe3 Nd4 {here Black diverges from previous games, which continued ...Bb7. The most recent example:} (17... Bb7 18. Nf3 Kh8 19. Qd2 Re8 20. Rfe1 Qe7 21. Qc2 h6 22. Qc4 f5 23. Qh4 Qxh4 24. Nxh4 Kh7 25. Rec1 Rbc8 26. Kf1 Ba8 27. Rc2 Rf8 28. Nf3 f4 29. Bd2 g5 30. Bc3 b5 31. gxf4 gxf4 32. Rbc1 Rg8 33. Be1 {1/2-1/2 (33) Lehmann,C (2100)-Borulya,E (2293) Germany 2008}) 18. b4 {White finally gets in the break with the b-pawn.} cxb4 19. axb4 Bg4 (19... a4 $5 {is preferred by the engine. The pawn is tactically defended, as Qxa4 would be followed by ...Nxe2.} 20. b5 Bg4 21. Nf3) 20. f3 {this is a committal and seemingly antipositional move by White, who temporarily shuts off the Bg2 and cuts off the f3 square from the Ng5. However, it's more dynamic than an alternative like Re1.} (20. Nf3 $5) 20... Bd7 21. Ne4 axb4 $6 {although Black still has a passed pawn after this trade, having an outside passed pawn on the a-file would be a greater advantage.} (21... a4 { is now an even stronger idea than before, since the passed pawn is protected by the Bd7.}) 22. Bxd4 exd4 23. Qb3 {White correctly is not in a rush to recapture the pawn, choosing to develop her queen first in an effective manner. } Re8 {lining up against the undefended e2 pawn and pinning the knight. This also frees up the f8 square for a bishop retreat.} 24. f4 {interestingly this appears to be White's only good move. It frees up the Bg2, most obviously, and her other pieces are already optimally placed.} (24. Qxb4 $2 {this would lift the pin on the f-pawn, to White's detriment.} f5 25. Nd2 Rxe2 $17) 24... Bf8 ( 24... h6 {would be a prophylactic move, taking away the g5 square from the knight.}) 25. Ng5 {another example of a patient master-level move. While Black has protected the b4 pawn, her pawn structure in the center and queenside is shattered and too vulnerable to protect in the long term. This means that White need not worry about the material deficit. Instead, she now starts a threat of her own against the weak f7 square. This threat trumps the previous pin of the knight against the e2 pawn, which we therefore can say has been tactically broken.} Be6 {an inaccuracy which allows White to gain some traction.} (25... Qf6 {or ...Qe7 defends the f7 pawn without allowing the minor piece exchange as in the game.} 26. Bd5 Rxe2 27. Nxf7 Kg7 $11) (25... Re7 {is also possible.} 26. Bd5 Be8 27. f5 Rxe2 28. Nxf7 Bxf7 29. Bxf7+ Kh8 $11) 26. Nxe6 fxe6 {in contrast with the above variations, Black no longer has the threat of ...Rxe2 because of the pawn on e6.} 27. f5 (27. Bc6 $5 Re7 28. Qxb4 { might be a simpler approach, regaining the pawn with the idea of pursuing play on the queenside. In the game, White instead prefers to increase pressure on the kingside.}) 27... gxf5 28. Rxf5 {taking advantage of the pin on the a2-g8 diagonal.} Rc8 {the best way to improve Black's position. She can't do anything about all of the air in front of her king, but she can activate the rook on the open file.} 29. Bd5 {an excellent, master-level move. White increases the pressure on the diagonal in the most effective way, while the bishop cannot be taken for tactical reasons.} Qd6 {Black appears to be trying to hold onto the extra material, in this case the b4 pawn, rather than placing her pieces on the most effective squares.} (29... exd5 $2 30. Rxd5 {and Black will lose material, due to the discovered double check threat.}) (29... Qd7 $5) 30. Rg5+ Kh8 31. Be4 {the bishop now needs to be moved, with the tactical threat of discovered check no longer there.} Rc5 32. Rg4 {exchanging on c5 would just help Black get her pawn structure in order.} b5 {I'm not sure of the point of this, which may simply be a waiting move. If so, bringing the rook back to c7 would create fewer potential problems, as we'll see shortly.} 33. Rf1 {bringing another major piece into the kingside attack.} Rc3 34. Rf7 { threatening mate on h7.} Rc7 {now we see why this would have been better played earlier, as Black is simply a tempo down.} 35. Rf5 {again using tactical themes involving the e6 pawn. The pawn remains pinned, but this time against the mating square g8 rather than the Black king.} Bh6 $6 {under pressure, Black finally cracks. She was probably focused on getting rid of the mate threat on g8, which is now covered by the Re8. She also probably saw the threats she could make after placing the bishop on e3, but White is able to easily parry them.} (35... Rc5) 36. Rxb5 $16 {now we see another drawback of Black's move 32. She now has no material compensation for her positional difficulties.} Be3+ 37. Kg2 Qf8 38. Bf3 {shutting down any threats on the f-file.} Rc1 39. Qxb4 {ignoring the check on g1. This is also a characteristic of master-level play, as amateurs too often are afraid of checks.} Rg1+ 40. Kh3 {emotionally these kind of moves can feel awkward and scary, as the king has very limited squares. However, calculation shows that Black has run out of threats.} Qf7 $2 {it's not obvious at first glance why this is bad, although White is able to quickly achieve a won position. Black does not realize that she has effectively given up control over the 8th rank.} (40... Qxb4 {is judged best by the engine, although it will likely result in a winning endgame for White.}) 41. Qd6 $18 {and there is nothing Black can do to avoid mate or major material losses. The immediate threat is Qe5+, while the queen can also support exchanging off the Re8.} (41. Rb8 {is probably the easiest winning continuation to spot, although the text move is more elegant and decisive. The problem for Black is that her back rank is under-defended, given the control of the Rg4 over the g-file and Black's king in the corner.} Qh5+ 42. Rh4 Qf5+ 43. g4 Qf7 44. Qb7 Qxb7 45. Rxe8+ Kg7 46. Bxb7 $18) 41... Qf6 (41... Bh6 42. Qxd4+ Bg7 43. Qxg1 $18) 42. Rb8 Qh6+ 43. Rh4 Qg6 44. Rxe8+ Qxe8 {unfortunately for Black, getting rid of the 8th rank threat has now left her vulnerable again on the a1-h8 diagonal.} 45. Qe5+ Kg8 46. Rg4+ 1-0