Attack on the uncastled king: queen to f5 (c2·2)
c9-24839naming 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 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.
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 b1, queen c2, rook c1, bishop f2, knight h1 b3, pawn a2 d2 g2 h2 e3 f3.
Black: king c8, queen c4, rook a8 g8, bishop h4, knight c5 g6, pawn d5 e5 b7 f7 g7 h7.
12 white and 13 black pieces are on the board; the puzzle position arises after move 18.
The position in numbers
Black are ahead by 5 points of material (29 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 b1, the black king on c8.
It is White to move on move 18, with 32 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 6 pawns, Black 6. Files fully open (no pawns of either colour): c — natural highways for the rooks and queen. Half-open for White: b.
The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
18. Qf5+ Kb8 19. Rxc4 Nxb3 20. Rc2 Nxd2+ 21. Rxd2
Why it works
- Great move! queen to f5 keeps the pressure (+2.8).
- Well found: rook to c4 (+3.3).
- A natural move: rook to c2.
- Best move. rook to d2 is exactly what the engine plays (+3.7).
- You win a piece — the queen.
- If instead Kb8, then Rxc4 and you win the queen.
Move by move
- 18. Qf5+ — queen to f5 with check
- Kb8 — king to b8
- 19. Rxc4 — rook to c4 (capture)
- Nxb3 — knight to b3 (capture)
- 20. Rc2 — rook to c2
- Nxd2+ — knight to d2 (capture) with check
- 21. Rxd2 — rook to d2 (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.
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.
Discovered attack
A piece steps aside and opens a second attack from the piece behind it.
A discovered attack works like a curtain: one piece steps off the line and unveils the long-range piece behind it. The beauty is that the moving piece can create a second threat of its own — two attacks in one move. Look for your stacked pairs: a bishop or rook behind a knight or pawn, aimed through them at something valuable. Send the front piece to the most aggressive square — a discovery without a second threat wastes half its power.
About this position
These pieces come from starting position #346.
SP-346 · BastionScout — A knight on the a- or h-file, king on c or f — the mirror twin lands here as well.
The king starts on c1, the rooks on b1 and g1, the queen on d1.
The king already stands on c1, so castling long moves only the rook, from b1 to d1.
The bishops stand on e1 and f1; their long diagonals reach a5 and a6 once the d- and e-pawns step aside.
The second rank carries 2 pawns with no defender at all: a2, h2.
The setup belongs to the BastionScout family; read right to left it becomes position 325.
The engine's main line opens with c4.
Morozov Balance Index: 28 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +33 centipawns for White (depth 44, 400 000 000 nodes).
Explore position #346Provenance
Mined from the project's engine self-play games.
Pack 008 · SP-346
Similar puzzles
In your browser or in the Android app. Nothing to install · Free, no ads