Tuesday, November 30, 2021

More On Exchange Sacrifices

     Here is some more on the sacrifice of the exchange based on instructions from that master of attack, Rudolf Spielmann. 
     Spielmann observed that the absolute values are what form the basis on which most exchanges are made, i.e. Q= 9, R=5, B and N = 3 and P=1. However, it is the relative value that is the decisive factor for positional play and especially for sacrifices. To wit: 
 
1) The simpler the position, the more the absolute value carries weight. 
2) The more complicated the position, the more the relative value of the pieces gain in importance. 
 
     When it comes to the sacrifice of the exchange it is never an exactly even transaction so you either win the exchange or you lose it. Exchange sacrifices are dependent on specific positional and tactical factors. 
 
Spielmann offers the following helpful definitions: 
 
1) Any voluntary loss in material counts as a sacrifice. 
2) The sacrifice of the exchange is when a Rook is given up for a minor piece and a Pawn. 
3) The term sacrificing the exchange when applied to situations where a Rook is given up for a minor piece and two Pawns is incorrect; it should be wins two Pawns for the exchange. 
4) The sacrifice of the exchange can serve any purpose. It can be a sacrifice for: 
     a) Development 
     b) An obstructive sacrifice, a sacrifice intended to blockade a square, file, rank or diagonal. 
     c) A sacrifice designed to expose the opponent's King. 
 
     In all cases, the sacrifice of the exchange is designed to improve the position of the minor pieces. 
     Here is a case in point taken from the game Spielmann vs. Tarrasch that was played in Carlsbad 1923. Spielmann gave this game in his classic The Art of Sacrifice in Chess. A great attacker and sacrificial player, in this book he classified various tactical motifs, but as with almost all of those old books from pre-engine days, analytical errors abound in the examples. Still, there is a lot to be learned from the book and even if his evaluations and play in the following game were not always correct, they worked against the great Tarrasch which says something...we can learn ideas from them and maybe use theme in our own games.

Rudolf Spielmann - Siegbert Tarrasch

Result: 1-0

Site: Carlsbad

Date: 1923

King's Gambit Declined

[...] 1.e4 e5 2.f4 ♗c5 Statistically, at least in my database, this move produces much poorer results for black than accepting the game. White has a lot of ways to counter this move and many times black will end up with a much worse position than if he had accepted it. If black wants to decline the gambit then the Falkbeer (2...d5) is a better choice. The idea is that the B prevents white from castling. 3.♘f3
3.fxe5 Is a trap that loses for white. 3...♕h4+ 4.g3 (4.♔e2 ♕xe4#) 4...♕xe4+ wins the R.
3...d6 4.c3 Other options are 4.Nc3 and 4.Bc4, but the text is considered slightly better. 4...♗g4 This pin is somewhat annoying and the method white uses here to counteract it originated with Frank Marshall. 5.fxe5 dxe5 6.♕a4+ ♗d7 7.♕c2 ♘c6 8.b4 This is the point as black's next move is forced. 8...♗d6 Necessary, else 9 P-N5 wins the King Pawn.
8...♗b6 9.b5 ♘a5
9...♘ce7 is much worse because after 10.♘xe5 ♘f6 11.a4 white's position is even better than after 9...Na5
10.♘xe5 winning the e-Pawn.
9.♗c4
9.b5 isn't so effective now as seen in Huschenbeth,N (2532)-Azarov,S (2635)/Greensboro USA 2014 9...♘a5 10.d4 and now black could have equalized with 10...c6. Instead he played the much weaker 10...♕e7 and white got the upper hand after 11.♗d3 f5 12.♗g5 ♘f6 13.♘bd2 h6 14.♗xf6 gxf6 15.O-O
9.♘a3 does not give white much. 9...f5 10.d3 ♘f6 11.♘c4 O-O 12.a4 a6 13.♗e2 h6 14.O-O is equal. Bakhtiari Kish,M (2056)-Dilanyan,G (2296)/Erevan 2016(21)
9...♘f6 10.d3 ♘e7
10...h6 11.O-O O-O 12.a4 a6 13.♘bd2 b5 14.♗b3 equals. Popovych,O (2305)-De Lange, D (2210)/Gausdal 1982
10...♕e7 11.O-O O-O-O 12.a4 a5 13.b5 gave white a huge advantage in Bronstein,D-Panov,V/Moscow 1947
11.O-O ♘g6 12.♗e3 This permits black to obtain counterplay. 12.a4 was correct. 12...b5 13.♗b3 a5 14.a3 axb4 15.cxb4 Black's Q-side advance has succeeded in forcing white to play this which has resulted in black achieving full equality. 15...O-O
15...♗xb4 is refuted by 16.♗xf7+ ♔xf7 17.♕b3+ ♔e8 18.♕xb4 Although the material is equal white is much better.
16.♘c3 c6 17.h3 ♕e7 18.♘e2 ♗b8 The purpose of this move is to exchange Bs after ...Ba7 in the hope of establishing a N on f5, but the maneuver is somewhat labored. The immediate 18...Nh5 was simpler. 19.♔h2 ♗a7 20.♗g5 h6 21.♗xf6 ♕xf6 22.♘fd4 ♕d6 23.♘f5 ♗xf5 24.♖xf5 ♘f4 25.♖f1 Up to this point black has defended himself ably and picked up a positional advantage in the better P-formation because white's Ps on a3 and d3 are backward and may become weak. For his part white has built up strong pressure on the f-file which Tarrasch seems to underestimate. (Spielmann) Actually, white's last move gives black a slight advantage, but he must play accurately because the slightest slip will give white tactical chances. It doesn't matter how great a positional advantage you have, miss a tactical shot and the positional advantage means nothing!
25.♘xf4 was correct. Then after 25...exf4 26.e5 ♕d4 27.♖f1 ♖ad8 28.♖5xf4 ♕xe5 29.g3 the chances would be about even as black must guard against the attack on f7.
25...g6 Her Spielmann makes the incorrect claim that it would be better to decline white's offer of the exchange implied by his last move and that black had little choice but to play 25...Ne6. The text move "wins" the exchange at the cost of enabling white's attack, hitherto directed only against f7, to spread over the whole K-side. (Spielmann)
25...♘e6 This move does result in an equal position so Spielmann is correct in that claim. 26.♕a2 ♖ae8 is completely equal.
26.♖1xf4 exf4 27.e5 Black can claim a slight advantage here...provided he finds the best moves...it is this difficult task that makes the games of great attackers like Spielmann, Nezhmetdinov, Tal and others so entertaining...in the complications their opponents often went astray. 27...♕e7
27...♕c7 With this move black would have kept his small advantage in hand. 28.♖f6 ♔h8 (28...♕xe5 A poisoned P! 29.♖xg6+ ♔h7 30.d4 wins) 29.♕c3 ♗e3 30.♖xc6 ♕d8 and black is doing OK.
28.♖f6 Spielmann has completely misjudged the position, not only did he do so during the game, he did so when he wrote the book! He wrote - "The powerful establishment of the R on this square is the point of the sacrifice. There are now many threats, above all 29.d4 and only then capture at g6 by either the R or Q. True, Black remains with two Rs for the Q, but his K-side is so critically weakened that successful defense is, in the long run, impossible. Yet this would be better than the defense which Bback actually selects." That's all wrong as any engine will tell you. Stockfish puts black's advantage at nearly 4 Ps, Komodo about one P while the ancient Fritz 5.32 puts it at about 3/4 of a P.
28.♕xc6 This move, unmentioned by Spielmann, would have drawn which is white's best course. 28...gxf5 29.♕g6+ ♔h8 30.♕xh6+ ♔g8 31.♕g6+ ♔h8 32.♕h6+ ♔g8 33.♕g6+ ♔h8 34.♕h6+
28...♔g7 I won't even bother quoting Spielmann here because his note is so far from reality! However, this is the losing move after which Stockfish evaluates the position as being almost 6 Ps in white's favor which is, obviously, a clear win.
28...♔h8 is another story...black is winning! 29.♕c3
29.♕xc6 ♕xe5 30.♖xf4 ♖ae8 This is even better than taking the N. Black has a won game in either case.
29...♗e3 The sacrifice on g6 is no longer a threat. 30.♖xg6 fxg6 31.e6+ ♔g8 32.♕xc6 ♖xa3 and the game is practically over.
29.d4 And now it's true...white is winning. 29...♗xd4 Tricky! Of course, white cannot capture the B at once. 30.♗xf7
30.♘xd4 White must leave the B alone! 30...♕xe5 There is nothing white can do. His best line is 31.♖xf7+ ♖xf7 32.♗xf7 f3+ 33.♔h1 fxg2+ 34.♔xg2 ♔xf7 35.♕xc6 ♖d8 36.♘f3 He needs the N to defend his K. 36...♕e2+ 37.♔g3 ♖d3 and all white has left is some meaningless checks.
30...♗xe5 This allows a mate in two, but he was lost anyway.
30...♖xf7 31.♕xg6+ ♔f8 32.♘xd4 ♖xf6 33.exf6 ♕f7 34.♕xh6+ ♔e8 35.♘f3 ♕f8
35...♖xa3 36.♘g5 ♕f8 37.♕g6+ ♔d7 38.♕f5+ and wins...the K has no safe retreat.
36.♕g6+ ♕f7 37.♕e4+ ♔d8 38.♕xc6 White has a won ending. For example... 38...♖xa3 39.♘e5 ♕h7 40.♕d6+ ♔c8 41.f7 forces mate in 11 moves.
31.♕xg6+ Facing mate next move, Tarrasch resigned. An entertaining game!
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