Among the most common uses of a sacrifice described in Chess Sacrifice as Chess Tactics, one was to gain time in promoting a passed pawn. This type of chess tactics to gain time is most likely to arise in the end game, particularly where both players are left with King and pawns. The preventive action against promotion become incumbent on the King only and the ability of the King to do so is dependent on the principle of the Square as was discussed in 4 endgame situations.
In the race to push the pawn to the last rank, if your own King is too far away to provide the support and the opponent King is ‘within the Square’, what is your only chance towards success? If you can throw something (meaning a pawn, in the situation under discussion) in the path of the opponent’s King such that it is unable to disregard it and has to take an action (meaning capture), the resultant delay of one move may force the enemy King to step out of the Square and your pawn laughs all the way to become a Queen!
The illustrative game was played between Aron Nimzowitsch and Siegbert Tarrasch, two stalwarts of their times, in the San Sebastian tournament of 1911.
Aron Nimzowitsch (1886-1935) was a Latvian hailing from Riga and was a challenger to Capablanca in 1925 for World Championship, but unfortunately for him this could not take place for want of adequate sponsorship. He had a quite revolutionary thinking about the theories on chess, running against prevailing concepts, and became a proponent of what came to be known at that time as the hypermodern school. Besides being a great theoretician, he was also a talented writer and his book titled My System published in 1925 is still regarded as one of the most important books on chess. His ideas on openings led to a good number of variations that go under his name, the most well-known being Nimzo-Indian Defense which has been very successfully used by Victor Korchnoi when playing as Black.
Dr. Siegbert Tarrasch (1862-1934) was born in Breslau, Germany and was a highly regarded positional player of his time. He also failed to secure a match in 1903 against Lasker, the World Champion at that time, due to a failure in negotiations. Unlike Nimzowitsch, his ideas were more in line with the classical approach of previous World Champion Wilhelm Steinitz but refined to an extent. He also contributed to opening theories with variations that bear his name. His ideas on positional play are still followed by players at all levels.
These two players had a running feud on what constituted the proper style of play as can be guessed from what has been said above and their rivalry was quite famous. Though we have not yet shown you any game by Tarrasch, you have seen a beautiful endgame from Nimzowitsch in the first game discussed in Endgame tactics: learn from master play.
However, in the diagram position at the end of 35 moves, you will see that Tarrasch had something to show to his younger rival.
|37.||Kg4||Rxf5||White avoided 37. Rxb5 as after 37. … axb5 the pawn cannot be stopped. So White tried first to bring his King closer to Black’s RP|
|38.||Kxf5||a5||Now White thinks of stepping inside the Square to stop the pawn and Black has to think on how to gain time to promote his pawn!|
|39.||Ke4||f5+!||White resigned as he is unable to guard against both the Black pawns|
You see how Black gains time by throwing the BP at White King!
If 40. Kxf5, the White King has to step outside the square and Black plays 40. … a4 to get it promoted.
If White disregards the Black BP and plays 40. Kd4, Black will first play 40. … f4 to stop White’s NP from advancing and then maneuvers his King to capture both the White pawns to promote his BP.
If you have doubt, you can count that White King needs 7 moves from its d4 square to be able to capture the RP and return to e2 square to guard against promotion of Black’s BP at f8.
But Black’s King needs 5 moves to capture both White pawns to stand at g2 square and 2 moves for the BP to move from f4 to f2 square, total 7 moves. As the Black King at g2 guards both the promotion square f1 and the BP at f2, the White King at e2 is helpless!
Watch the Game