Monday, March 9, 2015

Exchange sacrifices

Most clubplayers have sacrificed material in some games to launch an attack. However sacrificing purely for strategical or positional grounds is something which I almost exclusively see in games of more advanced players. Less experienced players don't grasp yet the abstractness of activity, strong squares or weaknesses. Obviously you only sacrifice material if you understand the value which you get in return.

In this category of sacrifices there is often used the exchange sacrifice. A player sacrifices the rook for bishop or knight. For most topplayers this is something very common but when I look in my personal database of standard games, I have to admit that it is rather rare in my practice. My non-attacking style (see gambits) doesn't explain everything as a game is always played by 2.

One of the very first times that I encountered an exchange sacrifice on the board, was in the Open Gent 2000 by the Belgian grandmaster Vladimir Chuchelov  (today not anymore an active player but a trainer of among others the number 2 of the world Fabiano Caruana)
[Event "Open Gent 4de ronde"] [Date "2000"] [White "Chuchelov, V."] [Black "Brabo"] [Result "1-0"] [ECO "A90"] [WhiteElo "2540"] [BlackElo "2265"] [SetUp "1"] [FEN "4b3/rp4r1/p1pn1k2/3pN2p/PP1P1Pp1/2KBP1P1/7R/7R w - - 0 42"] [PlyCount "7"] {(The remainders of the stonewall are taken down by a simple exchange sacrifice. )} 42. Rxh5 $1 Bxh5 43. Rxh5 a5 $2 {(A misplaced try to find activity.)} 44. Rh6 Ke7 45. f5 {(With a handful of seconds on the clock I had seen enough. Whites attack anyway crashes through.)} 1-0
A simple but efficient example of how quickly a defense can collapse after an exchange-sacrifice. Much more creative was my exchange-sacrifice in 2002 against Raf De Coninck.
[Event "H.V. Alcatel - Agfa Gevaert"] [Date "2002"] [White "Brabo"] [Black "De Coninck, R."] [Result "*"] [ECO "C78"] [WhiteElo "2284"] [BlackElo "2156"] [SetUp "1"] [FEN "3r3r/2kn1p2/p1nb3p/P1p1p1p1/1pP1P3/1N2BN2/1P3PPP/3RR1K1 w - - 0 25"] [PlyCount "13"] 25. Rd5 $5 Nf6 $2 {(Black takes the bait and gets into problems hereby. Better was to complete the development with e.g. Rhe8 and black is at least equal.)} (25... Rhe8 26. g4 Nd4 (26... Nf6 27. Bxc5 Nxd5 28. cxd5 Bxc5 29. Nxc5 Nxa5 30. Nxa6 Kd6 31. Nd2 $44) 27. Bxd4 exd4 28. e5 Bf8 29. Kg2 Re6 30. h4 gxh4 31. Nxh4 $13) 26. Bxc5 $1 Nxd5 27. cxd5 Bxc5 28. Nxc5 Nxa5 29. Nxe5 Rhe8 30. Ncd3 f5 31. f3 $14 {(Whites center dominates clearly over the exchange.)} *
Of course black should've refused the exchange but understood too late how large the compensation is. Sometimes sacrificing an exchange isn't fully objectively correct but it is an ideal practical tool to change the character/ course of a game. Such speculative/ practical sacrifice was played by Wouter Gryson in our mutual game. The complete game was earlier covered in the article the fake truth.
[Event "Interclub Deurne - KBSK"] [Date "2012"] [White "Brabo"] [Black "Gryson, W."] [Result "*"] [ECO "B06"] [WhiteElo "2334"] [BlackElo "2260"] [SetUp "1"] [FEN "r4rk1/2p2pbp/1q1ppnp1/N4b2/PPPP4/2BN1Q2/5PPP/R3R1K1 b - - 0 21"] [PlyCount "17"] 21... Rxa5 $6 {(A speculative exchange-sacrifice which was mainly justified by whites earlier large time-consumption. Objectively c6 is more correct but of course it is not a nice choice and it is doubtful if it generates better practical chances.)} 22. bxa5 Qb3 23. Rac1 Qxc4 24. Nb2 $6 { (More accurate is Nb4 and the extra material is probably sufficient for white if his technique does not fail)} Qb3 25. Qd1 $6 {(Surrendering the diagonal a8-h1 is not the best choice. Nd1, recommended by the engines is clearly superior. )} Qb7 26. Nc4 Nd5 27. Ne3 Nf4 28. d5 Bxc3 29. Rxc3 Be4 {(Black has managed to find a lot of counterplay for the exchange.)} *
The previous examples are clear but it is often much less evident. Last I had to decide to permit or not an exchange-sacrifice in my game against the Belgian FM Gorik Cools. In the end I chose to avoid the possibility but ended up in a dangerous position.
[Event "Interclub Hoboken - Deurne"] [Date "2014"] [White "Cools, G."] [Black "Brabo"] [Result "*"] [ECO "C69"] [WhiteElo "2260"] [BlackElo "2337"] [SetUp "1"] [FEN "2k1r1r1/2p1bn1p/pp3pp1/2pR1P2/4PBP1/1P4NP/P1P2K2/3R4 b - - 0 26"] [PlyCount "22"] 26... Bd6 $5 {(Objectively the best move but then you should not be afraid of the complications hereafter.)} (26... Rd8 $5 {(I was not able to calculate in a few minutes the complications after Bd6 so I chose for the prudent but passive Rd8.)}) 27. Bxd6 Nxd6 28. Rxd6 {(It was this exchange-sacrifice which worried me during the game.)} cxd6 29. Rxd6 Rd8 30. Rxb6 (30. Rc6 Kb7 31. Rxf6 Rd2 32. Kf3 Rxc2 33. Rf7 Kc6 34. Rxh7 Rc3 35. Kf2 Rc2 36. Ke3 Rc3 37. Kf2 Rc2 38. Ke3 Rc3 39. Kf2 $11) 30... Rd2 31. Ke3 $1 Rxc2 32. Rxa6 Kb7 33. Rxf6 Rc3 34. Kf2 Ra8 35. a4 Rxb3 $5 {(C4 is a serious alternative but the position stays approximately balanced if I trust the evaluation of the engines.)} 36. Rf7 Kc6 37. Rxh7 $13 *
So the exchange-sacrifice was surely playable but not winning. It is an open question what would've happened if I permitted the complications. Such reluctance exists much less with top-players. Still it was a big surprise in the previous worldchampionship that Anand dared to sacrifice the exchange in his last black-game especially as there were perfectly acceptable alternatives.
[Event "Carlsen-Anand World Championship"] [Site "Sochi RUS"] [Date "2014.11.23"] [Round "11"] [White "Magnus Carlsen"] [Black "Viswanathan Anand"] [Result "1-0"] [ECO "C67"] [SetUp "1"] [FEN "rr3b2/2p2p2/2k1bNnp/p1pNP1p1/P1P1K1P1/2B4P/5P2/3RR3 b - - 0 27"] [PlyCount "36"] 27... Rb4 {(Attractive but at the same time black goes all in. Carlsen shows with an impeccable technique that in this position the exchange is a bit more important.)} 28. Bxb4 cxb4 29. Nh5 Kb7 30. f4 gxf4 31. Nhxf4 Nxf4 32. Nxf4 Bxc4 33. Rd7 Ra6 34. Nd5 Rc6 35. Rxf7 Bc5 36. Rxc7 Rxc7 37. Nxc7 Kc6 38. Nb5 Bxb5 39. axb5 Kxb5 40. e6 b3 41. Kd3 Be7 42. h4 a4 43. g5 hxg5 44. hxg5 a3 45. Kc3 1-0
So exchange-sacrifices are certainly not always straight-forward. For defense and attack it is often a difficult balance. Personal taste, tournament-situation,... play an important role. However it stands firm that exchange sacrifices more or less guarantee creative positions and interesting complications. Did you play once such type of exchange-sacrifice (so not the famous sacrifice on c3 of the Dragon) and there was no direct tactical justification then write it down in a reaction !


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