Opposite-side castling: the race to the kings

Two attacks at once

When both kings have castled on the same side, pushing the pawns in front of your opponent's king is risky. They stand in front of your own king too. With opposite-side castling, one short and the other long, that problem goes away. The pawns going toward your opponent's king stand on the other side of the board from your own. Both sides can attack all out, and it becomes a race.

One of the best-known examples was played in the 1974 Candidates final, when Anatoly Karpov met Viktor Korchnoi in the Dragon Variation of the Sicilian, with the Yugoslav Attack.

Pawns first

White's attack starts with the pawns on the kingside. The h-pawn and the g-pawn advance to open lines against the king. Black's pawn on g6 is a good target: it gives White's h-pawn something to hit. White often gives away a pawn just to open a line, and it is worth the price if the rook on h1 or the queen gets through.

Trade off the defenders

In the Dragon, the bishop on g7 is both a defender and an attacker. It guards the squares around Black's king and aims along the long diagonal at White's queenside, where White's king stands. That's why White often plays Be3–h6 to trade it off. The same idea goes for the knight on f6, which protects h7: chase it away or trade it off, and the road opens.

Follow Karpov's attack from move fourteen:

Try the move that decided it yourself. The queen is already on h6.

Black's counterplay

Black's counterplay comes on the queenside, but mostly with the pieces. White's pawns there usually stay on their starting squares and give Black's pawns no hook to hit, so a pure pawn storm is usually slower than White's. What Black has:

• The rook on the half-open c-file, against c3 and White's king.
• The knight via e5 to c4, to trade off White's bishop.
• The exchange sacrifice on c3: the rook is given for the knight, and the pawns in front of White's king are broken up.
• The bishop on the long diagonal, which becomes dangerous as soon as it opens.
• The b-pawn forward, to open a line against White's king.

In the game Black did get rid of White's bishop and doubled the rooks on the c-file, but White's attack came first.

Common mistakes

• Slow moves. In a race every tempo matters. A move that neither attacks nor defends can be one too many.
• Pawn moves in front of your own king. They give your opponent's pawns something to hit and open lines the wrong way.
• Attacking when it is time to defend. If your opponent has got further, you have to stop the attack first.
• Keeping the defenders. The attacker wants to trade off the king's defenders, not their own attackers.

Remember

• With opposite-side castling both sides can storm with the pawns without exposing their own king.
• Open lines against the king, if need be with a pawn sacrifice.
• Trade off the defenders, like the bishop on g7 in the Dragon.
• Count tempi. The one who gets there first often wins.

The attacks often end in a sacrifice or a mating pattern. Read about them under sacrifice and checkmate patterns.

Updated November 14, 2026