One of the most famous quotes of Aron Nimzowitsch is: "A passed pawn is a criminal which should be kept under lock and key. Mild measures, such as police surveillance, are not sufficient." What did the famous Grandmaster mean? We are going to investigate the cases where a passed pawn appears to be stopped ('police surveillance' if we use Nimzowitsch's analogy) since a move forward would lead to her immediate liquidation. Yet in many cases the little soldier does exactly that. There are many reasons for such a suicide and today we'll discuss the particular case where a pawn gets sacrificed to clear her square for a Knight. As you all probably know, the best squares for most of the pieces and especially Knights is in the center of the board, so naturally it is mostly central pawns that get sacrificed for this purpose. The first example is a very famous game by the first World Champion.
In the next game the future World Champion Boris Spassky (who was ony 12 years old at that time) shows that he knew chess classics:
It is nice to see that the new chess generation still studies the games played over 100 years ago as the following game demonstrates:
Now let me show you two beautiful games of Tal where White won with the same clearing pawn sacrifice. Except in one of them the legendary World Champion was on the receiving end of the combination...
In the next game the British Champion uncovers the idea that later became one of the most powerful weapons White uses against the Modern Benoni set up.
Here you can see Jonathan Penrose ponders his 11.h3 move. Could he imagine that he was playing the game of his life?!