Attack on the uncastled king: queen to h8 (h7·4)
c9-27623naming 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 1200 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 f1, queen h7, rook c1 g1, bishop d2, knight e4, pawn b2 e2 f2 h2 a3 g3 d4.
Black: king f8, queen b3, rook g6 c8, bishop h8, knight a4 c6, pawn c4 a5 d6 e6 c7 f7.
13 white and 13 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
Black are ahead by 2 points of material (32 against 34; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on f1, the black king on f8.
It is White to move on move 18, with 41 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 7 pawns, Black 6. No file is fully open, so the heavy pieces have to be pried in. Half-open for White: c.
The White king has 3 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
18. Qxh8+ Rg8 19. Bh6+ Ke7 20. Bg5+ Rxg5 21. Qxc8
Why it works
- Great move! queen to h8 keeps the pressure (+6.0).
- Spot on — bishop to h6 (+6.2).
- Strong! bishop to g5 is the sharp choice (+6.1).
- Best move. queen to c8 is exactly what the engine plays (+6.2).
- You win a piece — the rook.
- If instead Rg8, then Bh6+ and you win the bishop.
Move by move
- 18. Qxh8+ — queen to h8 (capture) with check
- Rg8 — rook to g8
- 19. Bh6+ — bishop to h6 with check
- Ke7 — king to e7
- 20. Bg5+ — bishop to g5 with check
- Rxg5 — rook to g5 (capture)
- 21. Qxc8 — queen to c8 (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.
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 #107.
SP-107 · BastionGuard — Off-centre king (c/f), no knight on the a- or h-file.
The king starts on f1, the rooks on c1 and g1, the queen on a1.
Castling short simply swaps the two pieces: the king on f1 and the rook on g1 trade places.
A bishop starts in the corner on h1: it has a single diagonal, which the g-pawn unlocks, running out to a8.
One second-rank pawn starts with no defender at all: h2.
The setup belongs to the BastionGuard family; read right to left it becomes position 849.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 34 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +31 centipawns for White (depth 46, 400 000 000 nodes).
Explore position #107Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-107
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