The story behind the game
The opening round of the 2005 world championship produces a sharp Sicilian and then an unusual ending: White has two knights while Black has two bishops. Topalov’s central break starts the counterplay, and his bishops later find active diagonals. The final pawn move attacks a centralized knight and shows why piece activity must be reassessed after each exchange.
Take these ideas to your next game
- Check central breaks before attacking only on a wing.
- A centralized knight can create useful threats even before castling.
- Use bishop checks to gain a useful diagonal.
- A pawn move with tempo can change the balance of an ending.
Read the complete annotated game
Full game transcript, including the result and the answers. Original explanations by chessgames.info; game score from the sources below.
Qa5 is the strongest saved candidate in this position. Topalov played d5, challenging e4 in the centre, but the saved comparison prefers Qa5 by more than the exercise threshold. From a5 the queen attacks the knight on a4 and supports the pawn on b4. The historical break remains part of the replay, not the required exercise answer.
Nf4 gains activity with an attack on the queen. The queen moves to f2, and the position later simplifies into the two-knights-versus-two-bishops ending. Notice that the value of the knight jump is tied to tempo: Black improves a piece while requiring White to answer a direct threat.
Bd3+ gains a checking tempo from an active diagonal. The king moves to c1, and Black can bring his own king into the ending. With queens gone, a bishop’s long diagonal can restrict king movement across a wide area. Compare the bishops’ reach with the knights’ available entry squares.
f5 attacks e4 with the rear f-pawn. The historical score ends after this advance. The pawn on f4 stays in place, while the pawn arriving on f5 gains a tempo against the knight. That distinction matters: doubled pawns can have different tasks, and the bishop pair supports an active rather than purely static evaluation.
Result: 0-1. The recorded score ends here; it does not imply checkmate.
Think through the turning points
Move 10: Compare the break with a queen move
Instead of the historical d5, which queen move attacks the knight on a4? In the game: d5. Qa5 is the strongest saved candidate in this position. Topalov played d5, challenging e4 in the centre, but the saved comparison prefers Qa5 by more than the exercise threshold. From a5 the queen attacks the knight on a4 and supports the pawn on b4. The historical break remains part of the replay, not the required exercise answer.
Engine-supported alternatives
Qa5 · +0.64 · depth 17
Qc7 g4 Rb8 Be2 Be7 g5 Nh5 f4 g6 Bxh5 gxh5 Rhe1 · +1.20 · depth 16
d5 exd5 Nxd5 Bc4 N7f6 Bg5 Qc7 Bxd5 Nxd5 Rhe1 Bb7 Qe2 · +1.20 · depth 16
Move 18: Give the knight an active target
Which knight move attacks White’s queen on e2? In the game: Nf4. Nf4 gains activity with an attack on the queen. The queen moves to f2, and the position later simplifies into the two-knights-versus-two-bishops ending. Notice that the value of the knight jump is tied to tempo: Black improves a piece while requiring White to answer a direct threat.
Engine-supported alternatives
Nf4 Qf2 Nd5 Bg3 Qd8 Qe2 Qf6 Be5 Qg6 f4 h5 f5 · +2.18 · depth 18
Be7 Nf5 Qc6 Bxe7 Nxe7 Nxg7+ Kf8 Qe5 Rh7 Nxe6+ fxe6 Nc5 · +2.22 · depth 18
Rc8 Bg3 Qe7 Nf5 exf5 Qf2 f4 Qa7 Ne3 Bxf4 Be4 Qxa6 · +2.45 · depth 18
Move 31: A bishop check improves the position
Which bishop move from b5 gives check to the king on b1? In the game: Bd3+. Bd3+ gains a checking tempo from an active diagonal. The king moves to c1, and Black can bring his own king into the ending. With queens gone, a bishop’s long diagonal can restrict king movement across a wide area. Compare the bishops’ reach with the knights’ available entry squares.
Engine-supported alternatives
Bd3+ Ka2 Kc7 Nb2 Bxc3 Rc1 Kxb6 Nxd3 Rxg2+ Kb3 Bg7 Rc2 · -3.02 · depth 20
Bc6 · -2.42 · depth 20
Be8 Re2 Bf6 Rd2+ Kc7 a5 Bc6 Nc4 h5 h3 h4 Kb2 · -1.93 · depth 19
Move 40: Attack the centralized knight
Which f-pawn advance attacks the knight on e4? In the game: f5. f5 attacks e4 with the rear f-pawn. The historical score ends after this advance. The pawn on f4 stays in place, while the pawn arriving on f5 gains a tempo against the knight. That distinction matters: doubled pawns can have different tasks, and the bishop pair supports an active rather than purely static evaluation.
Engine-supported alternatives
f5 Nf6 Rd8 Rc1 Bb5+ Kf2 Bb4 Rc2 Rd2+ Rxd2 Bxd2 g4 · -5.40 · depth 20
Bb5+ Kf2 f5 Nd6 Bb4 Nxb5+ axb5 Rc1 Kc6 Kf1 Rd8 g3 · -4.70 · depth 20
Bb4 Rb1 Bb5+ Kf2 a5 Rc1 Bxc5+ Rxc5+ Kxb6 Rh5 Rd8 Nc3 · -3.89 · depth 20
Every piece has a part to play.
The opening round of the 2005 world championship produces a sharp Sicilian and then an unusual ending: White has two knights while Black has two bishops. Topalov’s central break starts the counterplay, and his bishops later find active diagonals. The final pawn move attacks a centralized knight and shows why piece activity must be reassessed after each exchange.
Look a little deeper
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Accessible evaluation values & provenance
Stockfish 17.1 · 75,000 nodes per position; 1,000,000 at key moments. Actual depth 13–20. Positive centipawns favour White; mate scores remain separate. Selective search is evidence, not proof.
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