Attack on the uncastled king: knight to f2 (d1·5)
c9-24701naming tag (square·N)Opens in the app if installed, otherwise downloads the APK.
The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Uncastled king: the enemy king is stuck in the centre — punish it before it castles.
Winning tactic: there is a move that gains a decisive advantage — find it.
Difficulty 1610 ShuffleRating — for advanced tacticians.
White to move — find the best continuation
How to recognize this tactic
In Chess960 the pieces start on unfamiliar squares, so tactics appear earlier and from unusual angles. Do not trust classical patterns — read the actual lines of the bishops, the rooks and the queen from where they really stand in this position.
An uncastled king in the centre is a standing target. Look for ways to open the central files and diagonals against it with checks and threats before it can shelter — every tempo the king spends in the middle is a chance for a combination.
This position hides a concrete tactic that wins material or mates. Start with the most forcing candidate moves — checks, captures and threats — and calculate each to a clear end before choosing; the winning line is usually the one the opponent cannot meet.
General method: before you move, list the forcing candidates — every check, every capture, every direct threat — and calculate those first. The solution to a tactic is almost always among them.
Position on the board
White: king e1, queen g7, rook a1 c5, bishop g1 a8, knight d1, pawn a2 b2 d2 g2 h2.
Black: king e8, queen a6, rook f8, bishop d6 g8, knight e5, pawn a7 d7 e7 h7.
12 white and 10 black pieces are on the board; the puzzle position arises after move 16.
The position in numbers
White are ahead by 6 points of material (33 against 27; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on e1, the black king on e8.
It is White to move on move 16, with 47 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 4. Files fully open (no pawns of either colour): c, f — natural highways for the rooks and queen. Half-open for White: e.
The White king has 0 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
16. Nf2 Bxc5 17. Qxe5
Why it works
- Great move! knight to f2 keeps the pressure (+3.1).
- Well found: queen to e5 (+3.3).
- You reach a winning position (+3.3).
- If instead Bxc5, then Qxe5 and you stay on top.
Move by move
- 16. Nf2 — knight to f2
- Bxc5 — bishop to c5 (capture)
- 17. Qxe5 — queen to e5 (capture)
Types in this puzzle
Deflection
Force the defender away from its duty — then strike what it guarded.
Deflection forces the guard to leave its post: a sacrifice or exchange drags it away from the piece or square it protects. First find the critical defender — the piece whose absence makes the mate or the material win possible. Then find the move it cannot ignore, which is usually a capture. Do not be stingy: if removing the guard wins the queen or mates, the sacrifice pays for itself many times over.
Uncastled king
The king lingered in the middle — punish the delay.
Punishing the uncastled king: your opponent delayed castling, and now his king is stuck on its starting square under fire. In Chess960 this is deadlier than in classical chess — the king may start in the center or near the edge, and the familiar defensive setups simply do not apply. The signs: the victim still holds castling rights, and the files toward his king are half-open. Open lines before the king manages to hide.
Trapped piece
The attacked piece has no safe square — it is caught.
Trapping a piece means the attacked piece has no safe square left — it simply perishes. Do not chase it around; build a cage instead: cut off the escape squares with pawns and pieces first, and attack last. The typical victim has wandered deep into your camp or is stuck at the edge of the board, where its mobility is tiny. And always check the way home for your own raiders — or the trapped piece will be yours.
About this position
These pieces come from starting position #604.
SP-604 · ThroneScout — A knight starts on the edge (a/h) and the king sits centrally on d or e; the mirror twin stays in this family too.
The king starts on e1, the rooks on a1 and f1, the queen on c1.
The kingside rook already stands on f1, so castling short moves only the king, from e1 to g1.
The bishops stand on b1 and g1; their long diagonals reach h7 and a7 once the c- and f-pawns step aside.
One second-rank pawn starts with no defender at all: g2.
The setup belongs to the ThroneScout family; read right to left it becomes position 268.
The engine's main line opens with f4.
Morozov Balance Index: 0 of 100 — class D — largest edge. Engine evaluation of the starting position: +81 centipawns for White (depth 45, 400 000 000 nodes).
In 50 self-play games White scored 63.0% (95% CI 49.1–75.0%).
Explore position #604Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-604
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