Attack on the uncastled king: queen to d4 (e4·2)
c9-13553naming 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.
A fork made possible by the Chess960 piece placement.
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 1150 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.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
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 e4, rook d1 g1, bishop a1, knight d3 g3, pawn a2 e2 f2 b3 h3 g4.
Black: king e8, queen h8, rook d8 g8, bishop d5 b8, pawn d4 g5 b6 a7 e7 f7 h7.
13 white and 13 black pieces are on the board; the puzzle position arises after move 12.
The position in numbers
White are ahead by 2 points of material (34 against 32; 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 12, with 43 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 7. Files fully open (no pawns of either colour): c — natural highways for the rooks and queen. Half-open for White: d.
Black hold the bishop pair, an edge in open lines. The White king has 4 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
12. Qxd4 Qxd4 13. Bxd4
Why it works
- Great move! queen to d4 keeps the pressure (+4.2).
- Well found: bishop to d4 (+4.0).
- You reach a winning position (+4.0).
- If instead Qxd4, then Bxd4 and you stay on top.
Move by move
- 12. Qxd4 — queen to d4 (capture)
- Qxd4 — queen to d4 (capture)
- 13. Bxd4 — bishop to d4 (capture)
Types in this puzzle
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
Battery
Two pieces stacked on one line — the front one strikes with double force.
A battery stacks two long-range pieces on one line — a queen behind a bishop on a diagonal, or doubled rooks on a file. The front piece strikes with double force: capture it, and the piece behind recaptures with even more pressure. The battery is ready when both pieces already stare at one point and only the front strike is missing. Build batteries in advance on lines leading to the king — the doubling itself often breeds the combination.
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 #272.
SP-272 · ThroneGuard — The king starts in the middle of the back rank, on d or e, and neither knight begins in a corner.
The king starts on e1, the rooks on d1 and g1, the queen on h1.
The queenside rook already stands on d1, so castling long moves only the king, from e1 to c1.
A bishop starts in the corner on a1: it has a single diagonal, which the b-pawn unlocks, running out to h8.
The pawn on f2 is defended by the king alone — the classic soft spot of the standard setup.
The setup belongs to the ThroneGuard family; read right to left it becomes position 591.
The engine's main line opens with g3.
Morozov Balance Index: 1 of 100 — class D — largest edge. Engine evaluation of the starting position: +58 centipawns for White (depth 42, 400 000 000 nodes).
In 50 self-play games White scored 62.0% (95% CI 48.2–74.1%).
Explore position #272Provenance
Mined from the project's engine self-play games.
Pack 007 · SP-272
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