There was a saying: “When Tal sacs, take and check. When Fischer sacs, take and resign. When Petrosian sacs, just resign”.
What about Botvinnik? The famous strategist made many positional sacrifices, but usually with no escape for his opponents.
We’ll take a look at Knight sacrifice for two pawns. Pawns alone are not enough of compensation for a piece. So player has to seek for positional elements in his favour, but elements which have “permanent” (long-term) character. Some of those positional elements are: supported outpost, strong pawn center, open file, opponent’s strong pieces elimination etc.
White: Mikhail Botvinnik
Black: Ludek Pachman
Oberhausen 1961
This was a rather uneventful King’s Indian game with lots of pieces’ shuffling, but finally Pachman pushed f6-f5 and provoked White’s reaction.
1. Nf5!
Sacrificing knight for two pawns and one tempo (time unit in chess, one tempo=one move). 1. ef5 gives nothing because of 1…Nd4 and 2…Bf5.
1…gf5 2. ef5 Ng7 3. g4!
Only three moves after the diagram, the position has dramatically changed. White has a pawn-wall on the king side, but this is not an attacking formation. The first purpose of this wall is to keep Black pieces on passive squares. Ng7, Bf8 and Bd7 have no good moves. The only active piece is Nc5, but soon White will start to press all over the board.
3…Re5 4. Bd4 Re1
4…Bf5 attempt fails to 5. gf5 Rf5 6. Bg7
5. Re1 Re8
This is a slight mistake, but it’s not easy to give good advice for Black. Now the light bishop has no e8 square. It was better to regroup with Be8-Bf7.
6. Rd1!
Avoiding the trade, pressing over the d-file and keeping the e8-square blocked for light bishop. Botvinnik always knew which pieces to exchange and which to keep on the board.
6…Bc8 7. b4 ab4 8. ab4 Na6
The last Black active piece is pushed back and White owns the e4-square now.
9. Ne4 Re4
Black is forced to give material back as Nf6 was a deadly threat.
10. Be4 Nb4 11. Qd2 d5 12. cd5 cd5 13. Bf3
The game was adjourned here, and Black resigned the same evening.
