The move f4 - Crime and Punishment

Many chessplayers consider the move f4 in a twofold respect - as a rational move which proceeds accurately after castling kingside, and a dangerous move which opens the e1-h4 diagonal that leads to the king.

And Indeed, the move f4 can either be a rational move, or a very risky one. When f4 is played before the castling, the open e1-h4 diagonal creates a huge weakness in White's position. When you learn how to exploit this weakness, you are already on the winning side.

Today I played a wonderful game. The game started with the Sicilian Najdorf. After a few moves, my opponent suddenly made a careless mistake - he played the move (f4) before castling, and was checkmated immediately thereafter.

This game demonstrates the devastating attack against the opponent monarch after the move f4 is played:  

To exploit the aforesaid weakness (i.e. an open e1-h4 diagonal) you will need the following things:

1. a queen on d1 and a bishop on e2 (NOTE: If you start the attack with the natural move Bh4+ your opponent will block the e1-h4 diagonal with the move g3, and at the same time attack your bishop. For this reason, it's important to have both your queen and bishop on the d1-h4 diagonal, as shewn in the above game.  You can let your opponent take your bishop (gxh4) and then play the desicive Qxh4+!!)

2. A knight on f6 that will jump to g4 and clear the way for the bishop and queen. When you play the Sicilian Defense (like I did in my game) more often than not your knight will attack the opponent's dark square bishop on e3. The attack on the dark-square bishop along with the threat to play Bh4+ will be enough to ensure victory.

Here is the most prominent example of how risky 1. f4 is. 

Auch, that hurts!

hello little Raskolnikov