Attack on the uncastled king: knight to f5 (g3·15)
c9-09108naming 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 1480 ShuffleRating — club-player level.
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 g1, queen g6, rook a1 g2, knight g3, pawn a2 b2 e4 c5.
Black: king f8, queen f4, rook a8 h8, bishop c6, pawn b5 e6 f6 a7 d7.
9 white and 10 black pieces are on the board; the puzzle position arises after move 21.
The position in numbers
Black are ahead by 1 points of material (26 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 g1, the black king on f8.
It is White to move on move 21, with 31 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 4 pawns, Black 5. Files fully open (no pawns of either colour): g, h — natural highways for the rooks and queen. Half-open for White: d, f.
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
21. Nf5 exf5 22. Qxf6+ Ke8 23. Qxh8+
Why it works
- Great move! knight to f5 keeps the pressure (+4.3).
- Well found: queen to f6 (+4.5).
- Strong! queen to h8 is the sharp choice (+4.8).
- You win a piece — the rook.
- If instead exf5, then Qxf6+ and you stay on top.
Move by move
- 21. Nf5 — knight to f5
- exf5 — pawn to f5 (capture)
- 22. Qxf6+ — queen to f6 (capture) with check
- Ke8 — king to e8
- 23. Qxh8+ — queen to h8 (capture) with check
Types in this puzzle
Royal fork
A fork with check: the king must move, and the second piece is lost.
A royal fork is a fork with check — one of the two targets is the king itself. The check must be answered first, so nobody is left to rescue the second piece. Look for squares where your piece gives check and simultaneously attacks an undefended queen or rook. It is the most reliable fork of all, because your opponent literally has no choice.
Only move
Everything else loses — find the only move that holds.
An only move is a position where everything loses except one single continuation. You cannot play "by hand" here: run through fundamentally different defenses — run away, block, trade, counterattack — and discard the ones that fail. The hallmark of these puzzles is that the obvious moves lose quickly while the solution often looks strange. First understand exactly what the threat is — then the one saving move reveals itself.
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.
About this position
These pieces come from starting position #596.
SP-596 · BastionScout — The king starts one file off-centre, on c or f, and a knight begins in a corner.
The king starts on f1, the rooks on a1 and g1, the queen on d1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
The bishops stand on b1 and c1; their long diagonals reach h7 and h6 once the c- and d-pawns step aside.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the BastionScout family; read right to left it becomes position 270.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 93 of 100 — class A — most balanced. Engine evaluation of the starting position: +11 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #596Provenance
Mined from the project's engine self-play games.
Pack 011 · SP-596
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