Thursday, November 29, 2012

Exchange Sacrifice for Containment

I found a great game by Kasparov where he sacrifices an exchange to contain a piece. Kingcrusher has a nice video so I will link to that rather than inputting the game myself. I will focus on an analysis of sidelines in upcoming posts. Kasparov - Shirov Horgen 1994
This is a very popular game and features highly in many top games lists including Informant's best games of all time collection. Link at chessgames.com
Now lets get to analysis. I will start with the position after 22...Qb8:

Some commentators have pointed out 22...Ra2 as a possible improvement. I will look at that position later on. Now it is White to move:
Minor Pieces: White has an extra one at the expense of a rook. The d5 knight is quite well placed. The c4 knight is also threatening. The key to the position is the restriction of the Black knight on b7. The d3 bishop is there just to be out of the way. The Black bishop on g5 is Black's best minor piece.
Pawn Structure: White has a passed b pawn which can become of use towards an ending. The Black d6 pawn is backward and is one of the features of the position restricting the b7 knight.
Space: A slight edge to White in overall terms but the key feature here is the lack of squares for the b7 knight except for d8 which was just vacated by 22...Qb8. This is probably why Shirov selected that move. A routing such as Nb7-d8-e6-d4 solves all of Black's problems. White has to move quickly to keep Black from unravelling.
Material: Not to state the obvious but Black is up an exchange for a well posted knight on d5 and a restricted Black knight on b7.
Files/Ranks: Black has control of the a file.
Development: White is a bit behind as White has not castled yet. This is not however a position for ordinary moves. White needs to make some hay before Black solves the story of b7 knight.
Initiative: Each side I would say is fighting for this. Black is looking to unravel and White is looking to get some concrete threats in.
What problems does White have to solve?
1. Keep Black bottled and restrict opportunities for Black to get the rooks into the game.
2. Attend to king safety
I confess 23. h4 as played would probably not be my first choice of move. Given that White is down material I would probably consider this as a possible way to get the rook into the game via a rook lift. I do see the point now about making the Black bishop move off the confluence of two active diagonals. 23...Bh6 was played in the game. What if 23... Bf6 or 23... Bd8 ? Let's have a look:
After 23... Bf6:

24. Nf6 is tempting but that gives up White's best piece. The idea of playing 24. g4 and continuing an attack is interesting. Some concrete variations would need to be evaluated given the awkward situation of the White king. Also worthy of consideration and a move to me which feels correct intuitively is 24. Ncb6. That move especially seems worthy of a deep think. White threatens to win back the exchange but Black has some shots down the a file. A worthwhile practical analysis task. I will take a hard look and post my evaluation in an upcoming post.
Evaluation of 24. Ncb6:
24. Ncb6 Ra3 25. Nd7 Qa7 26. Nf8 Ra1 27. Bb1 Kf8 28. O-O Nd8 29. Qh5 the bad position of the b1 bishop limits White's game here. I can see some play trying promote the h pawn but all very unclear. The Black knight can dominate if it gets to d4 or f4. I would say an edge to Black or unclear.
24. Ncb6 Ra3 25. Nd7 26. N5f6 gf6 27. Qg4 Kh8 28. Nf8 but this f8 knight is awkward enough that I cannot find a convincing line for White. 28... Ra1 29. Ke2 Rh1 30. Now what? Black is about to play Qa1 and start driving the White King. The d3 bishop cannot assist much. If this is all White can get I'm going to look at other lines before looking deeper here.
The problem with the routing of the knight via b6 seems to be that it does nothing for king safety. White needs a plan to make use of pieces where they are as much as possible and especially the h1 rook. More lines upcoming.

Evaluation of 24. g4: I like this move because it opens a square for the White king on g2 and makes ...Nd8 for Black awkward since White has g5 trapping the Black bishop. Black can consider playing that as a sacrifice in some situations. Also in White's favor here is that the White rook can be used directly on the h file. The c4 knight can be routed via e3 to f5 or just posted on e3 for defense. Black's second rook is still cut off on f8 and Black has to solve the problem of the b7 knight. Some concrete variations:
24. g4 Ra2 ( for argument's sake ) 25. Kf1 Qa7 26. Qf3 Black may be able to afford playing with a rook for 2 pieces after 26... Nd8 27. g5 Bg5 28. hg5 Ra1 ( 28... Ne6 is playable also and may be a better move. I originally thought this was not possible but now I see that it is since the Black queen on a7 covers the e7 square and prevents Ne7. The whole line seems quite playable for Black honestly. ) 29. Kg2 Rh1 30. Kh1 since material is reduced and there is no specific threat in the position. I give White an edge but Black has solved the problem of the b7 knight and the White king is a bit exposed, the d3 bishop needs something to do. I feel White is ok here and given that 24. Ncb6 didn't seem to generate anything specific I may have to play into the unclear complications of this line. Another possible move here is simply to route the c4 knight to f5 via e3 now that the Black bishop is off of the c1-h6 diagonal. I will come back to that another time.
Position after ...Qa7:
This is my next analysis task. If I got this position in a game 15 game on ICC I would be very tempted to play something like Bb5. That gets the bishop out of a possible pin after ...Qa3. If I had more time I would consider Kasparov's move Nd7 and not that I would have played it. Since I now know it atleast draws let me try and calculate it out. Analysis in the next post.
Analysis after 27. Nd7 Ra8:
I know this is covered in the kingscrusher youtube video. I tried to visualize the line and I was just missing one bit of the puzzle for a while:
28. Ne7 Kh8 29. Qf7 Rd3 30. Nf8 Qa2 31. Nfg6 hg6 32. Ng6 Kh7 33. Nf8 and here I was asking myself why not 33... Rf8? And it took me a bit to realize that after 33... Rf8 White has 34. Qa2 which by no means is all that clear in any case but probably ok for White. Black has 3 pieces for the queen but the Black king is a bit exposed, the b7 knight needs a few moves to be useful and White has some counterplay with the b4 pawn. Black I think can certainly play that way for a win. If Black eschews that then White has a perpetual check w/ Nf8-g6-f8.
Position After 29...Qa3: This is the beginning of a series of unexpected moves:
30. Qf5 With the threat of Qd7. The bishop at d3 cannot be captured. 30... Ke8 ok perfectly understandable 31. Bc4 Rc2 32. Qh7 Why allow the bishop to be captured now? Because it sets up a knight fork collecting the exchange. Can Black do better than lose the exchange after 32. Qh7 ? This is my next analysis task.

Thursday, November 22, 2012

T55 Round 2

I obtained a draw in round 2 of the T55 tournament on ICC. I consider that something of an achievement as I was defending for most of the game. Here's the game with some comments.
Time to learn the opening a bit better.

Tuesday, November 20, 2012

Passive Exchange Sacrifice For Attack

Here's a nice example of a passive exchange sacrifice vs the long castle position.

I will post my analysis of how Black can play after 2. Bc1 and 3. Bc1 in upcoming updates. Analysis of Black to Play After 2. Bc1:
Here's my Reassess Your Chess style analysis of the position.
1. Minor Pieces - The Black knight on c4 is the star of the show with the Bf6 making a good performance in a supporting role. The White bishops are an endgame advantage but are currently quite defensive and not striking at much. A clear edge to Black here.
2. Material - Currently equal 3. Development/Time - Black is better coordinated.
4. Pawn Structure - An edge to White in an endgame but once again Black is well positioned to advance on the a and b files. The d5/d6 duo cuts down the influence of the White bishops. Black will try for a KO in the middlegame. White has some chances in an ending of drawing or winning.
5. Files/Ranks - Black can make good use of the c file. White has the e file on which there is nothing much to strike at. Edge to Black.
6. King Safety - Edge to Black for the moment. White should try and complicate with a possible Rf1, Rxf6 idea.
My assessment - A small advantage to Black but White is not without defensive resources and chances to win an endgame.
How to Proceed for Black: 1. Keep White from untangling. To this end ...Rfe8 comes to mind. Drive the White queen off a strong square and prevent Bd3 w/ Qh7# ideas. The White Queen most likely moves to g4 which seems to lead to a queen trade which favors White. This is now revealed to be a key resource for White in the position. Qg4 for is an annoying move to deal with. So an immediate Rfe8 and Black has to deal with a queen trade most likely which would seemingly end any chance Black has of an attack. 2. ...Ne5 cutting out Qg4 ( Bg4 also ) is an interesting idea. Black needs to avoid some exchanges and keep White bottled a bit longer to get a more significant advantage. Black can then proceed with Rc7 and Rfc8 ideas but White will not be idle in that time. White should try and target f6/f7 with Rf1 and make the above plan a bit awkward for Black. A line such as 2... Ne5 3. Rf1 Be7 4. Qf5 and White is well on the way to equality or better. So 2...Ne5 while interesting is a bit slow. 3. The pawn sacrifice ...g6 is also an interesting move but I cannot find a line which improves Black's edge. Black simply does not have sufficient development to justify a pawn sacrifice. If White captures Bh6 then ...Rfe8 Qf3 ...Be5 Bc1 and now I cannot find anything for Black which justifies a pawn down situation. 4. I'm starting to feel that Black's edge here is optical. The Bc1 is a nice defensive piece but also targets h6 in some lines. White can trade the knight on c4 if needed and the bishop on f6 is threatened in the short term with an exchange sacrifice. Black has to spend some time preventing that which should give White time to unravel enough to force off some pieces atleast. Time to look for a favorable route to a better or atleast equal endgame. There's no direct path I see to a continued edge in a middle game. 5. 2... Rfe8 3. Qg4 Qg4 4. Bg4 is a bit awkward for Black. 2... Rce8 ( sad but so ) 3. Qg4 Qg4 4. Bg4 Be5 with the idea of f5 and mobilizing the kingside majority is a possibility worth considering. Black should not be worse here I don't think but probably not better. 3. Qg4 is not forced but White doesn't have any seriously meaningful squares for the queen. I think this is a safe option to play.
2... Ne5 3. Rf1 Bg5 is worth a thought. If 4. Bg5 hg5 5. Bd3 Black may have to weaken the kingside pawns a bit to make sense of the whole idea of playing 2...Ne5 and 3...Bg5. This doesn't feel comfortable. Lets see. 5... g6 the g5 pawn is weak but on the other hand Black is setting up a powerhouse knight on e5. The White bishop is somewhat restricted by the d5 pawn but still has some scope. Black needs to keep the queens on to play this way. The Black rooks have scope to attack on the c file and my sense is that White will win the g5 pawn and then it will be a race. Could be exciting chess.
After the deliberation I am of the opinion that Ne5 is Black's best chance to continue the attack. In that line White has a safe continuation in 3. Bg4 which seems to force some simplifying exchanges unless Black wishes to risk an exchange sacrifice for some uncertain complications. In this line Black can play safe by playing 3... Ng4 4. hg4 Rfe8 5. Qf3 Re1 6. Re1 and now Black needs to choose a safe option such as Rce8 or a more aggressive idea such as Qc7. 2... Rce8 seems to be a safe way to simplify and/or reach an endgame.

3. Bc1:
This is already too late. Black wins after 3...Na3 because 4. ba3 Qc3 wins. So 4. Ka1 Qc2 ( or Nc2 ) I believe wins.
3. Qd3 seems to be a better defensive try. Black can continue with 3...Ne5 when White should probably offer some exchanges with 4. Re5 Be5 5. Bc8 Rc8 and good defensive changes due to the reduced material.

Sunday, November 18, 2012

Interesting Piece Sacrifice

I found the piece sacs in the following game fun to evaluate. I didn't use a computer to check everything but I do think the ideas are sound because the Black pieces are out of position.
Now I posted this because I decided to analyze 3...Kf7 in detail. If you like try it out and compare notes with me. Remember I'm not using a computer to do this. I will post my analysis below in a few days. I'm setting up the position as above and writing out my ideas for how to respond to any of numerous moves Black can play after 4. Bh6 which I think is the best follow up.
First Try:
3... Kf7 4. Bh6 Rg8 The Rook defends the bishop and prevents immediate material losses. 5. Nf4 g5 I'm sure there's a better move but this is interesting. 6. Qg6 Ke7 ( Life is much easier for White if Black tries 6 ...Kf8 7. Bg7 Rg7 8. Ne6 Ke7 and now I like 9. Qg7 and if 9... Ke6 10. Rf1 causes Black some unsolvable problems. ) 7. Bg7 gf4 8. Bf6 I think this is a key move. This Bishop is needed on a diagonal which can reach d8 later on in my critical line. 8... Kd7 ( 8 ...Ke6 9. Qf5 Kf7 10. Bg5 Kg7 11. Qf6 Kh7 12. Qh6# If 10... Ke8 then 11. Qe6 wins ) 9. Qf7 Kc6 10. Qg8 I could not find a direct win but White is now ahead 2 pawns. 10... Rc2 There may be better moves but I think Black is worse even when recovering a pawn. 11. Rc2 Nc2 12. e5 Kb6 12. Qb8 I think that's the key move. The threat is to play Bd8 and win the bishop.
FYI I did all that from the initial position in the diagram above without moving the pieces. I did take notes while analyzing. More lines upcoming.
Next Try: 3... Kf7 4. Bh6 and now I really cannot find a better move than 4... Rg8 5. Nf4 and now just for arguments sake 5... Bc8 6. Qg6 Ke7 7. Bg7 Qb7 8. Nd5!
Black's pieces are just terribly misplaced in the starting position and White is able to take numerous liberties as a result. My take away from this is that crazy looking sacrifices ( Nf7 ) should be looked at if I have a feeling my opponents pieces are on bad squares. I will post more exchange sacrifice games I find of value to my chess development as I find them.

Friday, November 16, 2012

T55 Round 1

I was recently invited to play in the team 45 league on ICC and I played my first game today. This is the game with some brief comments. I felt like I was playing Black with the White pieces in that game. I need to look up 1. c4 b6. I clearly don't have any clue as to what to play for. I got into something like a pirc/modern position I would be all too happy to play with Black. Hanging tough and realizing I was playing Black with the White pieces helped me keep that game together. BTW I would suggest T4545 League Game of the Week as a worthwhile collection of games to look through.

Thursday, November 8, 2012

What the !

Every so often I look at a game where the annotator awards an exclamation for a quiet retreating move that neither starts or continues an attack nor defends a position in some clever way. This often happens in Chess Informant. When I have the time I try and make an effort to understand why the annotator awarded the praise and most of the time I don't get it. Luckily some of the games are also available in other games collections. Here is a case in point:

Wednesday, November 7, 2012

Back in the Game

Hello my friends. Thanks for visiting and I hope to publish more frequently than in the last few months. After a busy few months of chess during the summer I took a brief recess of a few weeks. I attended the US Open in Vancouver Wa, in August. What a great location for that tournament! My chess was so-so at this event and I have more than a few suspicions that my opponents were receiving extra cranial assistance during the games. Beyond that I have to admit the location itself was distracting. My rental was upgraded from a lunchbox to a Chevy Malibu: A great great touring car. I put 421 glorious miles of use into it in various jaunts in Oregon. Some pictures to follow. I was fortunate to see the boardwalk at Asbury Park NJ during the Boardwalk Open in October before Sandy busted through with a crushing combination of wind and surf. To all those affected please accept my deepest wishes for a speedy recovery. I'm taking a brief pause from tournament play for the next several months. I failed to achieve my goal of a 2000 rating but I think I would have succeeded minus the computer assistance. I'm going to focus on opening play and my favorite strategic theme the exchange sacrifice in the off months. Here is a nice game by the late Svetozar Gligoric from 1967: Here are some pics from Oregon: Oswald West State Park Rose Test Garden My Chevy Malibu Rental Multinomah Falls Oregon is fully worth the visit. Definitely on my list of places to visit every few years. Hey USCF please have a tournament in the Portland, OR area again soon!