18 February 2019

Commentary: Tata Steel 2019, Round 2 (Duda - Van Foreest)

Today's commentary game naturally follows from the earlier Tata Steel 2019 Round 1 game. Van Foreest (on the White side of a Caro-Kann Exchange) lost the earlier struggle against Anand, but then became a winner on the Black side of the same opening. This game is quite different, though, as White's early choice to vary his development scheme sends Black down a more classical path, instead of Anand's setup featuring an open g-file and opposite-side castling.

Some key takeaways from the game, for Caro-Kann players and in general:
  • The benefit to Black of exchanging light-square bishops
  • Conditions for being able to defend against White's ideas for pressure on the h-file
  • The key role of queenside counterplay (see moves 23-25) so as to not give White a free hand on the kingside
  • The recurrence of tactical ideas such as Ne4-d2, which eventually becomes decisive for Black
  • How either player could have chosen to go for a drawing line (perpetual) at different times

[Event "81st Tata Steel Masters 2019"] [Site "Wijk aan Zee"] [Date "2019.01.13"] [Round "2"] [White "Duda, Jan-Krzysztof"] [Black "Van Foreest, Jorden"] [Result "0-1"] [ECO "B13"] [WhiteElo "2738"] [BlackElo "2612"] [Annotator "ChessAdmin/Komodo 11.2"] [PlyCount "100"] [EventDate "2019.??.??"] 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Bf4 {an alternative try to the usual Bd3. White accelerates his seizure of the h2-b8 diagonal and does not let Black's queen get to c7.} Nc6 5. c3 Nf6 (5... Bf5 {is in alternative way to play, anticipating the Bd3 development by White and looking to exchange off bishops early. In the game, this happens much later and also results in a change of Black's kingside pawn structure.}) 6. Nd2 {the second most popular move in the database. White prepares to support Ngf3 after Black's next.} Bg4 7. Qb3 { a normal reaction by White, once the bishop ceases protecting the b7 pawn.} Qc8 {this is less committal than the alternative ...Na5.} 8. Ngf3 e6 9. Bd3 (9. Ne5 $5 {is an interesting idea here, but simply retreating the bishop to f5 seems to take any sting out of it.} Bf5 $11) 9... Bh5 {a relatively rare option, with ...Be7 being standard. The idea here is to retreat to g6 and exchange off the Bd3, which otherwise is well-positioned to target Black's kingside.} 10. O-O Bg6 11. Bxg6 {Komodo, in contrast to some other engines, assesses that it is better for White to not exchange on g6. For White, often the idea behind this exchange is to create a target for an h-pawn thrust, which is what in fact occurs later on.} hxg6 12. Rae1 {committing to a central/kingside strategy.} Be7 $11 {Taking stock of the position, Black has full equality. The light-squared bishop exchange has left Black solid on the kingside and White has no obvious advantage, although he can try for play on the h-file, as in the game. Duda's next move is a novelty in the database and was likely an attempt to introduce some uncertainty into the position, while again looking for chances on the h-file.} 13. g3 $146 {as we will see later, the idea of this move is to prepare the pawn thrust h2-h4.} (13. Ne5 {is a typical try by White that scores well in the database (67 percent), but should not objectively be a concern to Black. The database figures also seem to be skewed by lower-rated games.} Nxe5 14. dxe5 Nd7 {similar to the game continuation looks fine for Black.}) 13... O-O {no reason to postpone castling.} 14. Ne5 Nxe5 {Black chooses to remove the well-placed central knight immediately. Although not forced, this is an excellent defensive idea, as otherwise White typically starts developing tactical ideas on the e-file to target the e6 pawn, with a knight sacrifice a possibility later on g6 or f7.} 15. dxe5 Nd7 16. h4 { White follows up on his earlier idea of g3. Should Black be worried? As the defender in this type of position, the usual assessment is that after two minor piece exchanges, Black should be all right, since the sacrificial possibilities by White are limited. White will also need time to bring his other pieces to bear on the kingside.} Nc5 {puts the knight on its best square, kicking the queen and eyeing e4 and d3.} 17. Qc2 Qc6 {putting the queen on the long diagonal and improving its mobility. Now White's lack of a light-squared bishop to oppose it is highlighted.} (17... b5 {is what the engines like in this position, following up with ...Qb7 to put the queen on the long diagonal and give black the option of a minority attack on the queenside.}) 18. Re3 { this just ends up being awkward for White and wasting time. Presumably the idea was to eventually transfer the rook along the third rank.} (18. Nf3 $5) 18... Qa6 {pressuring the a-pawn and also placing itself on another useful diagonal.} 19. Qb1 {with this move, it's clear that White no longer has the initiative and must start responding to Black's threats.} Rac8 20. Kg2 { needed to clear the first rank for his rook to shift to h1.} b5 {now Van Foreest plays the pawn advance, gaining space and with the eventual idea of a minority attack along with the a-pawn.} 21. Bg5 Qb7 {although Black has been moving his queen often, each time it has been with a purpose and has improved his relative position. This time is no different, as the queen will still be well-placed on e7 after the exchange of bishops, and the a-pawn is now free to advance.} 22. Bxe7 Qxe7 23. Rh1 a5 24. Qd1 b4 {Black's counterplay on the queenside balances White's play on the kingside.} 25. Qg4 (25. h5 {would amount to the same thing after} bxc3) 25... bxc3 {active defense.} (25... Qb7 $5 {is another interesting way to defend.} 26. h5 d4+ 27. Rf3 bxc3 28. bxc3 dxc3 29. hxg6 fxg6 30. Qxg6 Rf5 $11 {and White has nothing better than a perpetual.}) 26. bxc3 Rb8 {Black again correctly emphasizes counterplay, threatening to go to b2 with his rook.} 27. h5 g5 {Van Foreest goes for the option that is equal, but allows him to keep going in hopes of a win. The correct decision, as it turns out.} (27... Rb2 28. hxg6 fxg6 29. Qxg6 Rxd2 30. Qh7+ Kf7 {is a perpetual for White.}) 28. h6 g6 {this defensive idea should be well known to Caro-Kann players, to prevent a breakthrough on the h-file.} 29. Nf3 {targeting the weak g5 pawn, but} Ne4 {holds everything together for Black. } 30. Re2 {covering the second rank against the threat of ...Rb2. However, this leaves the c-pawn hanging.} Nxc3 31. Rc2 Ne4 32. Nd4 {although Black is a pawn up, now White gets to have equivalent play for it, gaining the initiative in compensation. The main threat here is the knight fork on c6.} Rbc8 33. Nc6 Qa3 {preserving the a-pawn.} 34. Rhc1 Kh7 {another important defensive idea for Black, blockading the h-pawn to prevent a future sacrifice on h7. The h-pawn is now a long-term liability for White, especially in an endgame, when Black opening the h-file by capturing the pawn will no longer be of consequence. Black does have to be careful to manage potential threats from any occupation of the f6 square by White, however.} 35. Qe2 {now Black has to take care of his Ne4, which is out of squares after a White pawn advances to f3. Previously it could have gone to d2, with the tactical idea of Rxd2 followed by ...Qxc1. The Qe2 instead now covers the d2 square.} g4 {Black gives back the material so his pieces regain freedom of movement.} 36. Qxg4 Rc7 37. Qf4 {this appears to be a try by White to maintain winning chances.} (37. f3 {leads to lines where Black can win the a-pawn, but his queen is too exposed to White's rooks for it to matter, so essentially White can get a perpetual on the queen.} Nd2 38. Rc3 Qb2 (38... Qxa2 {doesn't gain Black anything either} 39. R3c2 Qa3 40. Rc3 Nb3 $11) 39. R3c2 Qa3 $11 {with a repetition of position to follow, whether Black takes the a2 pawn or not.}) 37... Rfc8 $15 {obvious and good. Now White has to be careful about the Nc6, which has only one viable square (d4), as well as his currently under-protected rooks.} 38. g4 $6 {White likely underestimated the consequences of Black's next move.} (38. Qg4 Qd3 $15) (38. Nd4 {bailing out with the knight is likely the best (and most practical) option.} g5 {now has much less sting, since the g4 square is available for the queen.} 39. Qg4 Rxc2 40. Rxc2 Rxc2 41. Nxc2 Qf8 $15) 38... g5 $1 39. Qh2 (39. Qf3 Qxf3+ 40. Kxf3 f6 41. exf6 Nxf6 {and the h-pawn will fall after} 42. Nd4 Rxc2 43. Rxc2 Rxc2 44. Nxc2 e5 {first preventing the knight's return to d4} 45. Ne3 Kxh6 $17 {and Black (at the GM level) should be able to convert the endgame with his extra passed d-pawn.}) 39... Nd2 $19 {using the same tactical idea with the knight move to d2 as before, but now threatening ... Qf3+. By this point, White is essentially lost.} 40. Rc3 (40. Qg3 {is objectively better, but still leads to a lost endgame, so White tries something else.} Qxg3+ 41. Kxg3 Kxh6 $19) 40... Qa4 {the only winning move, threatening the g4 pawn. It's not too hard to find, though.} 41. Qh5 {protecting the pawn, but now Black's queen dominates in the center.} Qe4+ 42. Kh3 (42. f3 Qe2+ 43. Kg3 Nf1+ $19) 42... d4 {passed pawns must be pushed! Now White's position collapses all over the board.} 43. Rg3 ( 43. Qxg5 $2 Rg8 $19) 43... Qf4 {threatening the f2 pawn as well as ...Ne4 with a double attack on the rooks.} 44. Rd1 Ne4 {an elegant finish.} (44... Rxc6 { is straightforward, but perhaps required a bit more calculation. Or Black just preferred winning with the text move.} 45. Rxd2 Rc3 (45... Qxd2 $2 46. Qxf7+ { with a perpetual.}) 46. Rb2 Rxg3+ 47. fxg3 Qf1+ 48. Rg2 Rc2 $19) 45. Rxd4 Nxg3 46. fxg3 (46. Rxf4 Nxh5 {and Black is a full rook up, with the Nc6 next to fall.}) 46... Qf1+ 47. Kh2 Rxc6 48. Qxg5 Rc2+ 49. Rd2 Rxd2+ 50. Qxd2 Rc1 0-1

01 February 2019

Exchange sacrifices (intentional and unintentional)

Unfortunately most of my exchange sacrifices to date have been unintentional ones.  In other words, my opponent is able to win the exchange (a rook for a bishop or knight) because of an oversight on my part, but then I fight on with some positional compensation.  In some cases I can even win (as in Annotated Game #161) by focusing on maximizing the effectiveness of my minor pieces and playing aggressively to target my opponent's weaknesses.  Of course, it's even better to focus on doing that before you're down material.

Deliberate positional exchange sacrifices are a characteristic of master-level games, where the compensation obtained is intentional, with long-term positional and dynamic benefits.  (If it's an exchange sacrifice that leads by force to a mate or material gain, then it's not a "positional" sacrifice and should be thought of more as a combination.)  Although there is always a certain element of guesswork to any sacrifice without forcing winning variations, it's an indication of mastery to be able to identify concrete gains on the board, as well to have an intuitive feel for when an exchange sacrifice is a good (perhaps best) option.  I think pawn sacrifices are a related concept, and I have had a similar experience with them in that regard, although recently I've started to deliberately incorporate sacrificial ideas with pawns into my thinking.

Perhaps the clearest definition and explanation (with well-chosen illustrative examples) that I've seen is "Positional Exchange Sacrifices" by IM David Brodsky over at chess^summit.  This is a topic that gets referred to a lot, but not many people take the time to address it in depth, so it's well worth checking out.

27 January 2019

Training quote of the day #21

The most intelligent inspection of any number of fine paintings will not make the observer a painter, nor will listening to a number of operas make the hearer a musician, but good judges of music and painting may be so formed.  Chess differs from these.  The intelligent perusal of fine games cannot fail to make the reader a better player and a better judge of the play of others.
-- Emanuel Lasker, World Champion 1894-1921
(Cited in The Art of Planning in Chess: Move by Move by GM Neil McDonald) 

Commentary: Tata Steel 2019, Round 1 (Van Foreest - Anand)

As mentioned in my previous game post, I'll again start working in commentary on master-level games to my rotation of training analysis. I think it's useful to alternate that with analysis of your own games, at least to some extent.  Different lessons can be learned, in part because the overall quality of play tends to be (much) higher.  I've found that with master games, often it's analyzing why they didn't play a particular line that is illuminating, in addition to critical turning points in games.

The below game is from round 1 of this year's (still currently ongoing) Tata Steel tournament. I selected it because Anand adopts an aggressive setup as Black in the Caro-Kann Exchange Variation that is deliberately designed to cause interesting dynamic and structural imbalances.  Essentially Black wants to exchange bishops on f5 and thereby open the g-file, while castling queenside.  I find Black's typical ideas to be more straightforward and understandable, although not necessarily easy to execute.  The dark-square weakness and White's space on the queenside serve to counterbalance things and engines give White a small plus out of the opening.  However, in the middlegame White runs out of productive ideas, then critically weakens his own dark squares, after which Black finds a threat using his advanced doubled f-pawn that White cannot handle.  Anand's finish is quite strong and worthy of remembering.

[Event "81st Tata Steel Masters 2019"] [Site "Wijk aan Zee"] [Date "2019.01.12"] [Round "1"] [White "Van Foreest, Jorden"] [Black "Anand, Viswanathan"] [Result "0-1"] [ECO "B13"] [WhiteElo "2612"] [BlackElo "2773"] [Annotator "ChessAdmin/Komodo 11.2"] [PlyCount "56"] [EventDate "2019.??.??"] 1. e4 c6 2. d4 d5 3. exd5 cxd5 4. Bd3 {the Exchange Variation has been making a comeback at high levels.} Nf6 (4... Nc6 {is the main line, forcing White to play c3 in response.}) 5. c3 {White plays it anyway, which eventually leads to a transposition back to the main line, at least for Black.} Qc7 {placing the queen on c7 this early used to be a quirky sideline. It's now more mainstream, I'm sure in large part due to its practical success. The main idea is straightforward, to take over the b8-h2 diagonal and prevent White from playing Bf4. As the queen wants to go here in most lines anyway, playing it early and preventing White's bishop from seizing the diagonal makes a lot of sense.} 6. h3 {this is seldom played. The evident idea is to take away the use of the g4 square from Black, for either the knight or bishop.} g6 {a new move in this position according to the database, but not a new idea in the Exchange Variation. Black looks like he is fianchettoing his bishop, but in fact the main idea is to play play ...Bf5 and then open the g-file.} 7. Nf3 Bf5 8. Ne5 { White holds off on the bishop exchange and places his knight on the e5 outpost, ready to take back on d3. This also potentially opens up f3 for his queen.} Nc6 {although this position isn't in the database, for Black it's a standard setup in the Exchange Variation. In this game, White is further behind in development than normal, with only two pieces out to Black's four.} 9. Bf4 { now White has essentially caught up, as Black will have to move the queen again either immediately or after an exchange on e5.} Qb6 (9... Nxe5 {it might seem under general principles that exchanging off White's central knight is a good proposition. However, leaving the a4-e8 diagonal open results in a small plus for White. For example, this continuation leaves Black's king in the center:} 10. Bxf5 Nd3+ 11. Bxd3 Qxf4 12. Bb5+ Nd7 13. Bxd7+ Kxd7 14. O-O $14) ( 9... Bxd3 {engines like this move, but it betrays the original idea of the variation.} 10. Nxd3 Qb6 11. O-O {and White has an easy game, while Black is solid but without real prospects.}) 10. Bxf5 gxf5 {this is what Anand was going for with the variation.} 11. Nd3 {this avoids a possible exchange on e5 and protects b2, but is still a backwards move of the same piece in the opening. Moreover, exchanging on e5 or taking on b2 for Black does not look dangerous.} (11. Nd2 Nxe5 (11... Qxb2 $6 {going pawn hunting will leave Black dangerously behind in development.} 12. Rb1 Qxa2 13. O-O Qa6 14. Ra1 Qb5 15. Qf3 $16 {with Rfb1 a threat.}) 12. dxe5 Nd7 13. O-O Rg8 14. Nb3 $14) 11... e6 { the standard consolidating move for Black in this structure.} 12. Nd2 {getting the final minor piece out.} Rg8 {by this point Black has achieved a dynamic equality. He has some longer-term structural weaknesses (including the h7 pawn and dark-square holes) but in return he has dynamic piece play and the half-open g-file.} 13. O-O O-O-O {the only real place to put the Black king, also developing the queenside rook.} 14. a4 {now that Black has committed with his king, White grabs some space on the queenside. This is not dangerous for Black, though, as a4-a5 is not yet possible.} Ne4 {improving this piece considerably, as the most it was doing on f6 was guarding h5. With Black's king tucked away on the queenside, though, that is not critical.} 15. Rc1 (15. Qh5 Rg7 $11) (15. f3 Ng3 16. Rf2 Be7 $11) 15... Bd6 {a case where exchanging minor pieces is clearly indicated for Black. White's dark-square bishop would otherwise help dominate the dark squares, while the Black counterpart has nowhere else as useful to go.} 16. Bxd6 Nxd6 17. b4 {this type of position is important for Caro-Kann players to understand. White's pawn thrusts on the queenside look scary, but Anand deals with them effectively.} Kb8 {taking the king off the c-file and removing it from potential tactics involving the rook opposite it. Also vacates the c8 square for another piece. This is a good example of a move that "doesn't do anything" immediate but is valuable in the long run, with White not having a concrete threat in the meantime.} 18. Qe2 ( 18. a5 Qc7 19. Nc5 Ne4 $11) 18... Qc7 {proactively retreating the queen. It was doing no good on b6 anyway, now it can move along the 7th rank and also is well-positioned on the b8-h2 diagonal.} 19. Qe3 {White with this move basically admits he has nothing on the queenside and tries to generate some action in the center.} Ne7 {improving his weakest piece. On c6 the knight was shut down by White's pawns.} 20. f3 $6 {perhaps attempting to be prophylactic and shut Black's knight out of e4. However, now White has a more serious dark-square weakness, absent his bishop, and it affects the space in front of his king, with g3 and e3 now becoming more vulnerable.} (20. Kh1 {would step away from the g-file and keep the balance.}) 20... Ng6 {Black's knight immediately gets into play. The threat is now f5-f4, as we shall see.} 21. Ne5 $2 {White must have miscalculated the impact of Black's next move.} (21. Kh1 { as in the previous note is more prudent, but Black still gets an edge.} f4 { the pawn is tactically protected, due to a "removal of the guard" being available if White takes with the knight.} 22. Qe1 (22. Nxf4 $2 Nf5 $1 { chasing away the queen and the Nf4's only protection.}) 22... Nf5 23. Rf2 { and White's pieces are awkwardly tied up.}) 21... f4 22. Qe1 Nf5 23. Nxg6 { this just clears the way for Black on the g-file, but White appears to be losing in all variations.} (23. Rf2 {would be analagous to the above variation, but now White has a lot more problems. The Ne5 is vulnerable to ...f6, among other things.} Ngh4 $1 {and White has no good response to Black's threats, including piling up on the g-file and playing ...Ne3.} 24. Nf1 (24. c4 { doesn't gain White anything after} Rc8 $19) (24. Ng4 h5 25. Nf6 Rg6 26. Qe5 Ne3 {and White loses material.}) 24... f6 25. Ng4 h5 26. Ngh2 Rg6 $19 {it's looking grim for White on the g-file and Black also has the ...e5 pawn lever coming.}) 23... Rxg6 24. Rf2 Rdg8 {simple and effective.} 25. c4 (25. Qe5 { exchanging queens won't help White.} Qxe5 26. dxe5 Nh4 $19 {and the g-pawn falls.}) 25... Ne3 {Black correctly ignores the attempt at counterplay on the c-file.} 26. cxd5 Nxg2 {no need to wait for the capture, as White's queen is now also en prise.} 27. Qe5 Qxe5 28. dxe5 Ne1+ {with the fork ...Nd3 to follow. A strong finish to the game by Anand.} 0-1

22 January 2019

Training quote of the day #20

Gukesh is unusual in that he doesn't obsess about his results. He plays every game to win. He tries to be flexible in his opening choices and he studies the classics. He is level-headed enough to know that this aggressive maximal approach is going to lead to losses every so often and he can shrug them off.
...His favourite player is the late Bobby Fischer...In his best games, Gukesh concocts a similar blend of classic positional build-ups coupled with sharp tactics. 
(From the article "Dommaraju Gukesh's journey to becoming India's youngest grandmaster" in the Business Standard)