The Ugly Castle
Even beginners know that castling is a very important part of an opening strategy since it moves your king away from the center into a comfortable home created by a rook and three pawns.
But what if the new king's house is not so cozy, since the roof provided by the three pawns has a huge hole in it?
Fischer via Wikipedia.
This is exactly what happened in the following famous game by Fischer:
Here is what Fischer wrote in his book My 60 Memorable Games:
"Petrosian and Tal both happened to stroll by the board at this instant. Petrosian made a wry face which looked to me like "Can Black do it and live?"
Fischer admits that Black's position looks ugly, but it has its positive sides: two bishops, a beautifully placed knight on e5 and a compact pawn mass. I am really surprised that he didn't mention the open g-file! In fact, this file is Black's main asset in positions like this when both opponents castle kingside.
In the following two games Black created deadly threats to white king using the g-file.
Of course Fischer wasn't the inventor of this strategic concept. Look at this famous game for example:
Fischer's iconic book and particularly his above-mentioned comment made the "ugly castle" quite popular in the Sicilian Defense. In positions with opposite-side castles, Black obviously cannot attack White's king using the g-file. Yet, by transferring the rook to g8, Black greatly improves his chances to defend his king and win the game with a counterattack on the opposite side of the board.
At some point this strategy was the favorite of GM Ilia Smirin:
Before you come to the conclusion that this concept is the best thing since sliced bread, let me warn you that the position of the king in the ugly castle is vulnerable. Fischer himself gives the following brilliant game as a warning:
When Anatoly Karpov was in a must-win situation in his Candidates' match vs. Nigel Short and played this system, he also discovered that Black's life there is not all roses:
It is better to do the ugly castling when both kings are on the kingside. It makes your own king safer and also you can use the open g-file for an attack!
In my old article I explained that we should establish ratings for chess games and openings. I give this system an NC-17 rating, meaning that a chess player's discretion is advised and it is not suitable for anyone rated under USCF 1500.