French 101: Exchange Variation

This game provides a nice introduction to the French Exchange Variation.  Black slowly outplays his opponent until disaster strikes at move 28. 

US Junior Championship: Sicilian Moscow Variation

After avoiding outright disaster in Round 1, Robson strikes back with the Black pieces in Round 2.  If you play the Sicilian Najdorf, you have to be prepared to deal with 3.Bb5+.  Here, Robson plays the "solid" choice, 3...Bd7, undoubtedly expecting to outplay his outweighed opponent in the long term.  Compare this game to G23, where Carlsen plays the less safe but more dynamic 3...Nd7.

King's Indian 101: Fianchetto Variation--7.b3

The usual move in the Fianchetto Variation is 7.Nc3, but here Beliavsky faces the rare 7.b3.  Black must keep a close watch against the queenside storm, as in many Fianchetto Variation games. 

King's Indian 101: Fianchetto Variation

The King's Indian Fianchetto Variation is reached by several move orders, but let's begin with the most straightforward. 

1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.g3 d6 5.Bg2 O-O 6.O-O

Let's agree on this as the starting position for the KI Fianchetto Variation.  The Queen's Knight hasn't been committed yet, unlike the other KI mainlines, and the light-squared Bishop is coming in on the long diagonal, instead of to the usual e2 or d3.  White is likely going to push the e-pawn two squares as in other variations, but even that's in question.   This variation usually lacks the wholesale assault by Black on the White position due to the extra protection afforded by the Bishop, and the center will tend to be more fluid than in the other mainlines (it's more difficult for Black to focus an attack on the kingside when the center is not closed). 

Now White usually plays 6.O-O, but note that because the KI is a hypermodern opening Black is not tying White down to any particular move order. Black has several moves, with the principal being 6...Nbd7.  Others include 6...Nc6, c6, c5, a6, Bg4, Na6, and Bf5. 

6...Nbd7  The Knight is not ideally placed here, of course, but it's going to support Black's play into the center at e5.  In response, White has the major move 7.Nc3, the often-played 7.Qc2, and the minor moves 7.b3 (see G124) and 7.d5.  We'll look at Nc3 in the main, consider Qc2, and handle the other two moves in subsequent games. 

I.  7.Nc3 and now 7...e5 (diagram) is the best by theory.  Black's equalization in this position is still in the future, but he has no weaknesses.  White has the better grip on the center, and the Black Knight at d7, however necessary, is going to have to move again soon.

8.e4 White also plays 8.h3 here, but it has little independent significance.  Black now plays 8...c6 almost half the time and 8...exd4 a little over a quarter of the time.  The other two common moves are 8...Re8 and 8...a6.  After 8...c6, play may continue 9.h3 Qb6 10.Re1 exd4 11.Nxd4 Ne8 and Black is okay.  Continuing, 8.e4 c6 9.h3 (9.b3 Re8 10.h3 exd4) 9...Qb6 10.Re1 (diagram) 

10...exd4 11.Nxd4 Ne8 (11...Re8 12.Nc2 Nc5 =) 12.Nb3 a5 13.Be3 Qb4 14.a3 and White is slightly better (diagram) due to a space advantage and better coordinated pieces. 


II.  7.Qc2 e5 (the alternative is 7...c6 and it may be objectively as good 8.Rd1 Qc7 9.Nc3 e5 with a slight advantage to White) 8.Rd1 Re8 (8...Qe7 Nc3 9.c6 e4 10.exd4=) 9.Nc3 c6 10.e4 (10.b3 and now while 10...e4 has been the move of choice, this position deserves closer attention) 10...exd4 (10...Qe7 and look particularly at 11.b3 or d5) 11.Nxd4 (diagram) and Black is okay. 

Now a couple of games.

Pirc 101: Austrian Attack

Robson plays a nice game against Molner in the 5th round of the 38th World Open. The opening is the Austrian Pirc. The move to pay attention to is White's 9th, e5. The Rybka 4 Book (Jiri Dufek) gives 9.Qb5+, which has been the principal practice over the board.

French 101: Classical in Jermuk

Tatiana Kosinteva beats Hou Yifan in a French Classical in Jermuk, Armenia.  While the novelty in the game is 11.Nd1, which is dubious, the bigger flaw in the game is Black's plan to exchange the light-squared Bishops.  Black position is left stretched out of shape, and Kosinteva drives the point home.

King's Indian 101: Fianchetto Variation

The Fianchetto Variation of the King's Indian is a popular way to avoid the mainlines of the opening in which Black will conduct an all-out assault on the kingside.  There are many ways to arrive in the Fianchetto Variation, including as in the below game.

1.d4 Sidetracks: Torre, London and Colle Systems, But Not Really

Bruzon takes the great Ivanchuk out of mainstream theory quickly, but to no good end.  White declines to go down a beaten path repeatedly until we reach the following position:

1.d4 Nf6 2.Nf3 e6 3.g3 d5 4.Bg2

A lot of known lines have been avoided to this point, but the game is at least now on the cusp of the Catalan.  ChessBase classifies this position with the Torre, London, and Colle systems, but it's none of these.  If you have a name for this, drop a comment.  Nevertheless, the position has been reached often, and Black's next odd-looking move can be described as an anti-Catalan: 4...b5  Perhaps the kid Carlsen has shown the old master a thing or two.  See the second game below.

King's Indian 101: Classical Variation--9.Nd2

This King's Indian comes from the 17th Correspondence World Championship.  White scores with the third of the big three White responses to the Mar Del Plata Variation of the King's Indian: 9.Nd2.  The move may only be inferior to 9.Ne1 and 9.b4 in terms of the times it has been played.  Play is often across the entire board as in this game, and here, Black simply wasn't able to hit hard enough on the kingside.  The novelty in the game is at White's 20th. 

King's Indian 101: Introduction Part IV--Sämisch Variation

Click here for Part I: Overview

Click here for Part II: Classical
Click here for Part III: Four Pawns Attack
Click here for Part V: Averbakh System

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f3  introduces the Sämisch Variation.  White fortifies e4 and employs a flexible system, including that the King can be tucked away to either side of the board.  Should Black play an early c5, the opening will often look more like a Benoni than a KI.  The main choice by Black now is 5...O-O; Black may also play 5...c6, 5...Nbd7, 5...e5, 5...Nc6, and 5...a6.  In response to 5...O-O, White has a major move, 6.Be3, and two minor choices, 6.Bg5 and 6.Nge2 (see G111).  After 6.Be3, Black has no less than seven moves that have been played more than 1,000 times in Mega 2010.  Kasparov has played five of them.  For purposes of this introduction, let's reduce the numbers by looking at 2600+ players, with the winning percentage, as always, from White's persepective:

6...e5  22 Games  47.7%
6...c5 20 Games  45%
6...Nc6 7 Games  57.1%
6...Nd7 5 Games  70%
6...c6  3 Games  83.3%
6...a6  3 Games  83.3%
6...b6  1 Game  50%

So, it's 61 games, with more than two-thirds of those games involving one of two moves: 6...e5 or 6...c5, with those two moves showing a plus on the Black side.  Unless there be any mistake, the players of the White pieces in all of the above games were also above 2600.  The thrust of this intro is to identify some of the major lines of play, and, as always, the details of the opening will be drawn out through games. 

A.  6...e5 and now White has 7. d5 and 7.Nge2, with mainline play as follows:

 1.  7.d5 c6 8.Qd2 cxd5 9.cxd5 Nbd7     
       
 2.  7.Nge2 c6 8. Qd2 Nbd7 9.O-O-O a6 (see G113)

B.  6...c5 and now White has 7.Nge2, 7.dxc5, 7.d5

1.  7.Nge2 (keeps the tension) Nc6 8.d5 (8.Qd2) Ne5 9.Ng3 e6

2.  7.dxc5 dxc5 8.Qxd8 Rxd8 9.Bxc5 Nc6 and Black's compensation is indicated by that in over 700 games, White has a mere 47% win rate despite the extra pawn.  (See G114)

3.  7.d5 e6 8.Qd2 exd5 9.cxd5 a6

C.  6...Nc6 (Panno Variation) 7.Nge2 (7.d5?! Ne5!) a6 8.Qd2 Rb8

Pat He Comes, Like the Catastrophe of the Old Comedy: Carlsen Victorious in Sämisch

Just as I was winding up a brief introduction to the Sämisch Variation, I checked in on TWIC to find that Carlsen played against it today versus Ponomariov.  I'll yield to the World's No. 1 for a day.  Here's the game.  Note Ponomariov's 6.Nge2 and compare it to 6.Be3 lines. 

King's Indian 101: Introduction Part V--Averbakh System

Click here for Part I: Overview
Click here for Part II: Classical
Click here for Part III: Four Pawns Attack
Click here for Part IV: SämischVariation

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Be2 O-O 6.Bg5

The Averbakh presents a small exception to the notion that it's White's fifth move that determines the line of th KI being played.  White usually plays 5.Be2, and that raises the Averbakh alert.  After 5...O-O, White, however, can transpose back to the Classical with 6.Nf3 or follow through with the Averbakh by 6.Bg5. (Diagram below.)

After 6.Bg5, Black is constrained from pushing 6...e5 because of the resulting pin on the Knight.  7.dxe5 dxe5 8.Qxd8 Rxd8 9.Nd5 Nbd7 10.Rd1.  Black's usual move here is 6...c5, but 6...Na6, 6...h6, and 6...e6 are played with some frequency.  6...Na6 deserves a separate post.  7.d5  (7.dxc5 Qa5 (7...dxc5 8.Qxd8 Rxd8 9.e5 Nfd7 10.e6 Nf6 11.exf7+ Kxf7) 8.Bd2 Qxc5 9.Nf3 Bg4) 7...h6 8.Bf4 (Diagram left.)  Now the most popular move is to go straight for the center-buster 8...e6, but 8...a6 deserves attention, too.  Now the position gets complex fast, and Black does need to sort out these complexities at home.  9.dxe6 Bxe6 10.Bxd6 (Diagram below right.)

The usual move now is overwhelmingly 10...Re8. And one question arising is whether the move no one plays, 11.Bxc5, is playable? 11...Qa5 12.b4 Qa6 and the position appears tenable.  Black is down two pawns, but has significant compensation.  More work is required.  After 10...Re8, the usual play goes  11.Nf3 Nc6 12.O-O Nd4 13.e5 Nd7 14.Nxd4 cxd4 15.Qxd4 Nxe5 16.Bxe5 Qxd4 17.Bxd4 Bxd4, where Black has almost enough compensation for the pawn. (Diagram below left.)

While this certainly an incomplete discussion of the Averbakh, we'll fill in the discussion with forthcoming games.  One thing that stands out in even a preliminary investigation of the this line is that there is tremendous potential for original analysis and computer research. 

Trompowsky: Nigel tromps Chuck in Havana

The Trompowsky is the bane of those who like to work things out from home.  What to do?  No less than 8 moves have been played by players rated over 2400 against the Trompowsky.  Here they are:

1.  Ne4  10261  53.8%
2.  e6      8441   54.4%
3.  d5      5599   53.6%
4.  c5      3863   50.6%
5.  g6      3093   57.3%
6.  d6      865     56.7%
7.  c6      488     50.9%
8.  h6      261     64.2%

Ivanchuk plays the principled move, 2...Ne4, and then takes the game off the heavily beaten path with 7...Qf5.  After 12 moves Black has exactly one pawn advanced as far as the 3rd rank.  White has a tremendous space advantage, but his army his scattered.  The game ultimately reduces to a Bishop and three pawns versus two Bishops, and with the draw in hand Short plays 37.Bg2?? ending the day. 

King's Indian: Some Preliminary Statistics

King's Indian Statistics

The following statistics were pulled from small subsets of the ChessBase Mega 2010 and Corr 2009 databases.  These statistics will be refined by specific variations and moves as the research into the KI goes forward. 

The two sets of statistics can generally be described as:
Mega 2010:  World class players doing state of the art research in advance of the game.
Corr 2009:  Skilled players using good software and hardware for every move.

Conclusions to be drawn are limited from the below numbers, but here's what I think can be made of them:

• White does slightly better than average against the King's Indian. 
• The Classical Variation scores solidly OTB, but only averagely in CC.
• The SämischVariation scores above average in both OTB and CC, but the CC sample is small.
• The Four Pawns Attack is held in low regard at top levels and the statistics support that. 

Mega 2010 Database: 2007-2010 Both Players >2575

Overall  55.6% (315 gms)

1. 5.Nf3 58.% (175 gms)
2. 5.Be2 48.8% (42 gms)
3. 5.f3 59.5% (37 gms)
4. 5.Bd3 58.7% (23 gms)
5. 5.h3 42.5% (20 gms)
6. 5.f4 37.5% (8 gms)
7. 5.Bg5 83.3% (6 gms)
8. 5.Nge2 50% (4 gms) 

Correspondence 2009 Database: 2006-2010 Both Players > 2450

Overall 57.9% (74 gms)

1. 5.Nf3 53.3% (46 gms)
2. 5.Be2 66.7% (9 gms)
3. 5.f3 70% (10 gms)
4. 5.Bd3 75% (2 gms)
5. 5.h3 66.7% (3 gms)
6. 5.f4 50% (3 gms)
7. 5.Bg5 --   (-- gms)
8. 5.Nge2 100% (1 gm)

King's Indian 101: Saemisch Variation--6.Nge2

There's no better player to study than Radjabov when it comes to the King's Indian.  First, he's played the KI 122 times in Mega 2010, which is an enormous number.  Second, he's scored well enough with the opening that it's a feat of courage to even roll out the moves d4, c4, Nc3 against him.  Prior to yesterday, he had a winning percentage in every variation of the KI except the Sämisch.  Today he has a winning record in that variation, too.  The first move to consider is Ponomariov's 6.Nge2.  This is a distinct second-line move, as 6.Be3 is far more often played. 

King's Indian 101: Introduction Part I

The King's Indian (KI) comes in and out of fashion at the Super GM level, but throughout history it's mainly been in.  Like the Najdorf, both Fischer and Kasparov championed its cause, and it was widely played during their eras.  More recently it has required some revival, and for that Radjabov gets much of the credit.  At the amateur level, it is safe to assume that the opening is always viable.  The basic starting position is typically reached from the first diagram, but if you've looked more than casually at the defenses to 1.d4, you know that this isn't quite the starting point of the KI.  Another major opening springs from this position: the Gruenfeld, which is marked by 3...d5.  The two openings are distinctly different and it's the rare player who can switch from one to the other without a wholesale change in repertoire. (Kasparov is an exception.)  The reason to play either opening, however, is largely the same.  1...Nf6 unbalances the position quickly, and results in increased opportunities for Black to play for the win.  In general 1...d5-based systems are more solid than those beginning with 1...Nf6, but the price is fewer wins with the black pieces.  In several of these KI variations, for example, Black is going to put everything into a kingside attack, and that's one of the reasons the KI is, and has remained, popular. 

The KI typically begins 1.d4 Nf6 2.c4 g6 3.Nc3 (top diagram)

First, it's important to note that the KI is at its core more a system than a concrete opening.  Theory in the opening, however, has advanced with such breadth and depth that the KI will still feel like a complex opening that has to be learned in detail compared to some other system-based openings, such as the London System.  White has a variety of ways to respond to Black's opening moves, largely because Black doesn't challenge White's control of the center for several moves and thus does nothing forcing.  This results in White having much lattitude.  In addition to 3.Nc3, White will also often play 3.Nf3 or 3.g3.  We'll return to these two moves later in "sidelines" and Fianchetto Variation posts.  After 3.Nc3, Black responds with 3...Bg7, again doing nothing to force White's reply.  And now we have the KI on the board. 

White will usually respond in one of three ways.  First and foremost, While will occupy the center with 4.e4.  This opportunity to establish the e-, d-, and c-pawns in this unchallenged way (see diagram at left) is rare and will usually be seized by White.  The major alternatives are 4.Nf3 and 4.g3.  More later on these.  After 4.e4, Black responds 4...d6.  The d-pawn most importantly secures and supports the e5 and c5 squares, as well as makes luft for the Knights and light-squared Bishop.  (One of the features that makes the KI a "system," is that it's unclear where Black's best break will come--e5 or c5?)  Black can and sometimes does castle first, but note that after 4....O-O, White has the option of playing 5.e5.  While White has better moves available than e5, this specific move order invites a complexity that Black had better be prepared to handle.  Back to 4.d6, note that White has a large space advantage (don't set out with the KI if that's bothersome), and a superb center.  The price is a slight lag in development and a weak d4 square (a square that can no longer be supported by pawns). 

And we've arrived at the point where White's next move will characterize and distinguish the mainlines of the KI.  Note that it is White who's going to largely decide which of these major lines shape the rest of the game.  This isn't surprising.  Because of the hypermodern nature of the KI, Black has done little to constrain White's choices, and White has four substantial options at the fifth move. 

(In addition to sidelines, we'll look at a fifth mainline in the KI --the Fianchetto Variation--in a separate post, which largely arises out of 3.Nf3 rather than 3.Nc3.) 

We'll briefly introduce each of the four mainlines and then explain them separately in future posts (click on the bolded title to be taken to a slightly more in-depth overview):

1.  The Classical KI:  1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 * 

As you might expect, there are many lines that will play out from the "Classical KI," including the Petrosian System, the Mar del Plata Variation, and the Exchange Variation.

2.  The Four Pawns Attack: 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.f4 0-0 6.Nf3

This is an ultra-aggressive approach that has largely been de-fanged at the upper echelons, but which is popular at the amateur level.  How could it not be? 

3.  The Sämisch Variation:    1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. f3 *

Also aggressive, and the subject of a Super GM game as recently as yesterday, which will be included in the next post.  See Ponomariov v. Radjabov in the King's Tournament in Medias, Romania, 6/17/10. 

4.  The Averbakh Variation: 1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Be2 O-O 6. Bg5 *

And note the consequences of Black playing 6...e5 at this point in time, beginning with 7.dxe5.  Take a look now, as Black has to constantly be alert to combinations in the middle of the board....  7...dxe5 8.Qxd8 Rxd8 9.Nd5, and Black has nothing better than to give up the exchange with Nxd5.  The Averbakh Variation thus prevents e5 for a time.

So, the "mental structure" is in place for assimilating the KI.  To summarize, we'll begin with

(a) the four major variations flowing out of 3.Nc3 d6 4.e4,

          (1)  Classical,

          (2)  Four Pawns,

          (3)  Sämisch, and

          (4)  Averbakh, then

(b) the major line of the Fianchetto Variation, followed by

(c) the "sidelines," which I'll divide into

          (1) major and

          (2) minor sidelines.

Sveshnikov 101: 9.Nd5...11.c4

Radjabov doesn't often get pushed off the board as in the game below.  The first move to pay attention to is 11.c4.  The notion is to secure the d5 square--the oft-stated drawback is that White does so while lagging in development.  This line deserves exploration.  Much more often played--about 10 times more often--is 11.c3. 

Semi-Slav 101: Ducking the Botvinnik Variation with 6.e3

If avoiding the Botvinnik variation is important, then it's probably better not to play 5.Bg5.  If you're intent to develop the bishop outside the pawn chain while avoiding the wildness of the Botvinnik, then 6.a4 is probably a better try.

Sveshnikov 201: Mainline 9.Nd5

The Sveshnikov is one of very few openings that I'm willing to play with either color. One author has tagged the opening The Easiest Sicilian, principally because the theory is relatively narrow, say, compared to the Najdorf.  The Sveshnikov makes up for its lack of breadth, however, by running deep in its theory.  The novelty in this game comes on move 26, and that's not unusal for the Sveshnikov.  Here, White dominates the center of the board, and that, among other things, allows White to save a tempo by keeping his King in the center.  Black's only play is based on the outside passed a pawn, which is too slow.

Walters,Gary (2343) - Mauro,Lucio (2355)

WCCC33PR04 ICCF, 20.04.2009 [Stockfish 1.7.1 JA 64bit (40m)]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 (6.Ndf5 is the only interesting alternative.) d6 7.Bg5 a6 8.Na3 b5 9.Nd5 Be7 10.Bxf6 Bxf6 11.c3 0–0 12.Nc2 Bg5 13.a4 bxa4 14.Rxa4 a5

A position reached in countless games, and it likely appears at least 2,000 times in your largest games database. Now White has a major and a minor option. The minor option is 15.Bb5.

(See, e.g., Kasparov,Garry (2812) - Van Wely,Loek (2636) [B33] Hoogovens Wijk aan Zee (2), 17.01.1999 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 9.Nd5 Be7 10.Bxf6 Bxf6 11.c3 0–0 12.Nc2 Bg5 13.a4 bxa4 14.Rxa4 a5 15.Bb5 Bb7 16.Nce3 Bxe3 17.Nxe3 Ne7 18.0–0 Rb8 19.Qd3 Qb6 20.Bc4 Bc6 21.Ra2 Rfd8 22.b3 Qc5 23.Rfa1 Ra8 24.h4 h6 25.h5 Bb7 26.Rd1 Bc6 27.Rda1 Bb7 28.Bd5 Bxd5 29.exd5 Rdc8 30.b4 Qxc3 31.Qxc3 Rxc3 32.Rxa5 Rb8 33.Ra7 Kf8 34.Rd7 Nc8 35.Rd8+ Ke7 36.Rg8 Rxb4 37.Ra8 Kd7 38.Rxg7 Rc1+ 39.Kh2 Rf4 40.Ng4 Ne7 41.Ra7+ Ke8 42.g3 Rf5 43.Rh7 1–0)

Black’s more common response to 15.Bb5 (other than Van Wely’s 15...Bb7) is 15...Ne7.

(See, e.g., Shirov,Alexei (2723) - Van Wely,Loek (2668) [B33] Amber-rapid 12th Monte Carlo (11), 27.03.2003 1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 9.Nd5 Be7 10.Bxf6 Bxf6 11.c3 Bg5 12.Nc2 0–0 13.a4 bxa4 14.Rxa4 a5 15.Bb5 Ne7 16.Nxe7+ Bxe7 17.Ne3 Rb8 18.Qe2 Qb6 19.c4 Be6 20.0–0 Qd4 21.Qc2 Bd8 22.Rd1 Qc5 23.Qd2 Bc7 24.Ra3 Rfd8 25.Rd3 g6 26.Nf5 Bxf5 27.exf5 d5 28.Qg5 d4 29.Rh3 e4 30.Qh6 Qxf5 31.Qxh7+ Kf8 32.Rf3 exf3 33.Qh8+ Ke7 34.Re1+ Qe6 35.Qh4+ f6 36.Qh7+ Kd6 37.c5+ Kxc5 38.Qxc7+ Kxb5 39.Rxe6 d3 40.Qc6+ Kb4 41.Re4+ Kb3 42.Qc3+ Ka2 43.Qa3+ 1–0)

Much more often played than 15.Bb5, however, is the move in the game, the major option. 15.Bc4 Now the common move, as in the game, is Rb8 15...Kh8 will usually transpose back to the main line after 16.O-O Rb8) 16.b3 (16.Ra2 is to be seriously considered. While the Rook is less actively posted at a2, there are variations ahead where the Rook slides along the 2nd rank to the Kingside. 16...Kh8 The King needs to get out of the Bishop’s line of sight and free the f pawn.

17.Nce3 White more often castles in this position, but there is no absolute need for White to remove the King from the center. White rather plans to play down the h file, and while this game is not decided there, the threats are ever present. Note that White will not castle in this game.) g6 (Black has played 17...Bxe3, but the idea is dubious and has scored poorly. Black should keep the Bishop pair. 18.h4 Bxh4 results in a highly dynamic position. Both Rybka and Stockfish need a substantial amount of time to turn the evaluation away from Black’s advantage and back to balanced.

19.g3 Bg5 White has sac’d a pawn to open the h file. Black has the Bishop pair, but has common Svesh weaknesses in a backward d pawn and weak a pawn. White’s structure is not remarkably better, but the Rook staring down the h file is a constant bother and the Knights are well posted.
20.Ra2 Thematic. White will return the Rook to play along the 2nd rank. 20...Bxe3 White was threatening to take over the game with 21.f4

21.Nxe3 Be6 Obvious and good. 22.Rd2 I think this is objectively best. This game is still in well-known territory, but is unclear. 22...Qe7 23.Rxd6 Still nothing that hasn’t been seen before.

23...Nd4 The Knight cuts off the White Rook, but obviously White had to be prepared for this. 24.Rd5 Nc6 The Rook is off limits. White will recapture with the Knight gaining a tempo on the Queen with the Black Knight still hanging. 25.Rd3 Bxc4 26.bxc4N And we finally arrive at a new position. Previously, the play had been 26.Nxc4 Qb7 27.Qd2 Nb4 28.Re3 Rfd8 29.Qe2 Nc6 30.Nd2 Qd7 31.g4 a4 32.Reh3 h5 33.Qe3 Qxg4 34.Rh4 Qg2 35.R4h2 Qg4 36.Rh4 Qg2 37.Rxh5+ Kg7 38.Rh7+ Kf6 39.R1h3 Qg1+ 40.Ke2 Rb7 Huschenbeth,N (2318)-Aulich,M (1996)/Kelheim 2007/CBM 122 Extra/1–0, but 26.Nxc4 offered little opportunity in my view to play for a win in CC. The point of bxc4 is that while the doubled c pawns are ugly, White is dominating the center of the board. There’s little time for Black to get the a pawn moving in a genuinely threatening manner. 26...Rfd8 27.Rd5 Kg8 28.Kf1 Rb2 29.Kg2 Qg5 [29...h5 30.Qc1 Rdb8 31.c5] 30.Qf3 h5 31.c5 Kg7 32.Nc4 Rb3 33.Rhd1 Re8 [33...Rf8!?] 34.Rd7+- Re7 35.Rxe7 Qxe7 36.Ne3 Rb8 [36...Rb5 37.Nd5 Qd7 38.Qf6+ Kg8 39.Qg5+-] 37.Rd6 Rc8 38.Qd1 Nb8 39.Qd5 a4

[39...h4 40.gxh4 a4 41.Ng4 Qxh4 42.Qxe5+ Kf8 43.Qf4+-] 40.Nc4 h4 [40...Rc7 41.Nxe5 a3 42.Nxf7 Qxf7 43.Qd4+ Kh7 44.Rd8+-] 41.Nxe5 a3 [41...Re8 42.c6 Rc8 43.gxh4+-] 42.Ng4 a2 43.Qd4+ [43.Qxa2?! Qxe4+ 44.f3 Qe1 45.gxh4 Rxc5±] 43...Kh7 44.Nf6+ Kh6 45.Qd2+ [45.Qd2+ Kg7 46.Qxa2+-] 1–0