Chess Openings: Prophylaxis

Hi, 

Today I'd like to talk about prophylaxis in chess.

Prophylaxis is a word of Greek origin that means to prevent or guard (phylaxis) beforehand (pro).

But what does this have to do with chess?
We can use this idea to stop our opponent from doing something, particularly something useful.

Let's take a look at an example.

This position is taken from a game played between Garry Kasparov and Anatoly Karpov in their 1986 World Championship match in London back in 1986, after 11 moves.

Here White played the move h3, which might look passive or senseless to most of us. However this move is surprisingly strong. To understand it, we need to know what was Black's idea. If we play any other move (let's say a3), then after 12...exd4 13.exd4 Nb6 14.Ba2 Bg4! 

We now see Black's idea. The bishop on g4 is pinning the knight, which is a key piece defending the central pawn on d4. Black has good development and would be doing great in this line.

The move h3 stopped this idea and White got a comfortable position himself and even won the game.

Have you played any interesting prophylactic move? Fell free to share them here.

If you want to know more about this, you can check my video lesson https://youtu.be/KfxRK_yxPyU