Double Exchange Sacrifice

After so many examples of Petrosian's Exchange Sacrifice, the next move in the diagrammed position is not hard to see. Black played 25...Rxe4. Petrosian wrote:

Why did Black sacrifice the exchange so 'light-heartedly'? Because he got for his Rook, in addition to a minor piece, a Pawn. 'Ceteris paribus' a minor piece plus a Pawn are good compensation for a Rook. Black has two Bishops now. His light squared Bishop is particularly strong, while the White Rooks have no operational freedom. It is quite clear that Black will strengthen his position and increase the pressure.

The game continued 26.Bxe4 Bxe4 27.Nc2 d5 28.Nd4 b4 29.cxb4 axb4 30.a4 Qa7 31.Qf2 Rc8 32.b3 Bf8 33.Nb5 Qa6 34.Qe2 Qb6+ 35.Kf1.

Bucharest 1953
Petrosian, Tigran

Troianescu, Octavio
(After 25.Nc2-e3)
[FEN "3r2k1/1q3pb1/2bpp1pp/pp6/2r1PP2/P1P1N1P1/1P1RQ1BP/4R1K1 b - - 0 25"]

I don't like to give long sequences of moves on Web pages, because few people are able to visualize the resulting position. If you have trouble following, see the usual Chessgames.com link at the end of this post. For the same reason, I won't give any of Petrosian's analysis on those moves.

Black's next move is really extraordinary -- 35...Rc3 -- sacrificing another exchange. White picks up another Pawn, making the compensation two Bishops and two Pawns for the two sacrificed Rooks. Add to this Black's advanced connected passed Pawns plus White's exposed King and it is clear that Black is winning. A few moves later White gave back an exchange, but the game was already lost.

To play through the complete game see...

Octavio Troianescu vs Tigran Vartanovich Petrosian, Bucharest 1953
http://www.chessgames.com/perl/chessgame?gid=1106236

...on Chessgames.com.