Attack on the uncastled king: bishop to d3 (b1·6)
c9-22901naming 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 1390 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 d1, rook c1 h1, bishop b1 b4, knight d4, pawn a2 b2 f2 g2 h2 c3 e5.
Black: king f8, queen c4, rook c8 h8, bishop b8 e8, knight b6 f6, pawn b5 a7 e7 f7 g7 h7.
14 white and 14 black pieces are on the board; the puzzle position arises after move 12.
The position in numbers
Black are ahead by 2 points of material (35 against 37; 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 12, with 6 legal replies to weigh — only the line that keeps the advantage solves the puzzle. White are in check right now, so every reply must answer the check.
White keeps 7 pawns, Black 6. Files fully open (no pawns of either colour): d — natural highways for the rooks and queen.
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
12. Bd3 Qd5 13. exf6 gxf6 14. Nf5 Bd6 15. Nxd6
Why it works
- Great move! bishop to d3 keeps the pressure (+2.6).
- Well found: pawn to f6 (+2.5).
- A natural move: knight to f5.
- Best move. knight to d6 is exactly what the engine plays (+2.2).
- You win a piece — the bishop.
- If instead Qd5, then exf6 and you win the knight.
Move by move
- 12. Bd3 — bishop to d3
- Qd5 — queen to d5
- 13. exf6 — pawn to f6 (capture)
- gxf6 — pawn to f6 (capture)
- 14. Nf5 — knight to f5
- Bd6 — bishop to d6
- 15. Nxd6 — knight to d6 (capture)
Types in this puzzle
Absolute pin
A piece is pinned against its king — it cannot legally move.
An absolute pin freezes a piece on the line between its own king and your long-range attacker: moving it is simply illegal. The pattern is three units on one straight line — your bishop, rook or queen, an enemy piece, and the enemy king behind it. A pinned piece neither attacks nor defends anything: treat it as if it were off the board. Pile up on it, ideally with a pawn, because running away is against the rules.
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.
Blocking save
Block the check with tempo — and turn the game around.
The blocking save: you interpose a piece against the check — not passively, but with tempo, so the blocker creates a threat of its own. Such a block turns defense into attack. Whenever you are checked, compare all three replies — capture, move the king, interpose — and among the interpositions hunt for the one that counterattacks. The mistake is automatically stepping aside with the king when an active block would have turned the game around.
About this position
These pieces come from starting position #232.
SP-232 · 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 f1, the rooks on c1 and h1, the queen on d1.
Castling ends where it always does: king to g1 and rook to f1 on the short side, king to c1 and rook to d1 on the long one.
The bishops stand on b1 and e1; their long diagonals reach h7 and a5 once the c- and d-pawns step aside.
One second-rank pawn starts with no defender at all: b2.
The setup belongs to the BastionScout family; read right to left it becomes position 637.
The engine's main line opens with d4, putting a pawn straight into the centre.
Morozov Balance Index: 31 of 100 — class C — noticeable edge. Engine evaluation of the starting position: +32 centipawns for White (depth 48, 400 000 000 nodes).
Explore position #232Provenance
Mined from the project's engine self-play games.
Pack 010 · SP-232
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