Exchange Sacs Flow From a Positional Advantage

I've reached the last game in Smyslov's Sparklers. In the sixth game of their 1957 World Championship match, Smyslov varied from his usual 1.e4 and Botvinnik adopted his opponent's weapon: the Gruenfeld Defense, Smyslov Variation. This can be a risky proposition, since the habitual player of an opening knows its nuances better.

In the diagrammed position White has built up a commanding positional advantage and played 20.c6. This might look routine until you consider that White was ready to sacrifice the exchange with 20...Nd3+ 21.Kc2 Nc5 22.Rxd8+ Rxd8 23.Rd1 Rb8 24.Rd7!, when Nxd7 25.cxd7 Rd8 26.Bc8 c5 27.b4 wins.

Moscow 1957 (Game 6)
Botvinnik, Mikhail


Smyslov, Vasily
(After 19...Rab8)
[FEN "1r1r2k1/pBp1p1bp/6p1/2P1Pp2/1n3P2/4P2P/PP2N3/2KR3R w - - 0 20"]

The game continued 20...Kf7 21.Nd4 e6 22.Nb5 Nd5, when White ended all resistance with another exchange sac: 23.Rxd5. Since 23...Rxd5 loses to 24.Nxc7 Rc5+ 25.Kb1 and 26.Na6, Black tried 23...exd5. He was overwhelmed by 24.Nxc7 Rdc8 25.Bxc8 Rxc8 26.Nxd5 and resigned a few moves later.

With this win Smyslov tied the match at two wins each. He went on to win the eighth game and finally developed his lead to +3, winning the title. To play through the complete game see...

Vasily Smyslov vs Mikhail Botvinnik, World Championship Return Match 1957
http://www.chessgames.com/perl/chessgame?gid=1032427

...on Chessgames.com.